Drugs that bind to but do not activate serotonin receptors, thereby blocking the actions of serotonin or SEROTONIN RECEPTOR AGONISTS.
A serotonin antagonist and a histamine H1 blocker used as antipruritic, appetite stimulant, antiallergic, and for the post-gastrectomy dumping syndrome, etc.
An ergot derivative that is a congener of LYSERGIC ACID DIETHYLAMIDE. It antagonizes the effects of serotonin in blood vessels and gastrointestinal smooth muscle, but has few of the properties of other ergot alkaloids. Methysergide is used prophylactically in migraine and other vascular headaches and to antagonize serotonin in the carcinoid syndrome.
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
A selective serotonin receptor antagonist with weak adrenergic receptor blocking properties. The drug is effective in lowering blood pressure in essential hypertension. It also inhibits platelet aggregation. It is well tolerated and is particularly effective in older patients.
A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties.
Drugs used to prevent NAUSEA or VOMITING.
An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses.
The forcible expulsion of the contents of the STOMACH through the MOUTH.
Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of serotonergic neurons. They are different than SEROTONIN RECEPTORS, which signal cellular responses to SEROTONIN. They remove SEROTONIN from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. Regulates signal amplitude and duration at serotonergic synapses and is the site of action of the SEROTONIN UPTAKE INHIBITORS.
A serotonin receptor subtype found widely distributed in peripheral tissues where it mediates the contractile responses of variety of tissues that contain SMOOTH MUSCLE. Selective 5-HT2A receptor antagonists include KETANSERIN. The 5-HT2A subtype is also located in BASAL GANGLIA and CEREBRAL CORTEX of the BRAIN where it mediates the effects of HALLUCINOGENS such as LSD.
A serotonin receptor subtype found distributed through the CENTRAL NERVOUS SYSTEM where they are involved in neuroendocrine regulation of ACTH secretion. The fact that this serotonin receptor subtype is particularly sensitive to SEROTONIN RECEPTOR AGONISTS such as BUSPIRONE suggests its role in the modulation of ANXIETY and DEPRESSION.
Compounds that specifically inhibit the reuptake of serotonin in the brain.
A serotonin receptor subtype found primarily in the CENTRAL NERVOUS SYSTEM and the CHOROID PLEXUS. This receptor subtype is believed to mediate the anorectic action of SEROTONIN, while selective antagonists of the 5-HT2C receptor appear to induce ANXIETY. Several isoforms of this receptor subtype exist, due to adenine deaminase editing of the receptor mRNA.
Endogenous compounds and drugs that bind to and activate SEROTONIN RECEPTORS. Many serotonin receptor agonists are used as ANTIDEPRESSANTS; ANXIOLYTICS; and in the treatment of MIGRAINE DISORDERS.
A serotonin receptor subtype found in the BRAIN; HEART; LUNGS; PLACENTA and DIGESTIVE SYSTEM organs. A number of functions have been attributed to the action of the 5-HT2B receptor including the development of cardiac myocytes (MYOCYTES, CARDIAC) and the contraction of SMOOTH MUSCLE.
Drugs that bind to but do not activate SEROTONIN 5-HT2 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN 5-HT2 RECEPTOR AGONISTS. Included under this heading are antagonists for one or more specific 5-HT2 receptor subtypes.
A subclass of G-protein coupled SEROTONIN receptors that couple preferentially to the GQ-G11 G-PROTEINS resulting in increased intracellular levels of INOSITOL PHOSPHATES and free CALCIUM.
A serotonin receptor subtype found at high levels in the BASAL GANGLIA and the frontal cortex. It plays a role as a terminal autoreceptor that regulates the rate of SEROTONIN release from nerve endings. This serotonin receptor subtype is closely related to and has similar drug binding properties as the 5-HT1D RECEPTOR. It is particularly sensitive to the agonist SUMATRIPTAN and may be involved in mediating the drug's antimigraine effect.
Drugs used for their effects on serotonergic systems. Among these are drugs that affect serotonin receptors, the life cycle of serotonin, and the survival of serotonergic neurons.
A subclass of G-protein coupled SEROTONIN receptors that couple preferentially to GI-GO G-PROTEINS resulting in decreased intracellular CYCLIC AMP levels.
An adverse drug interaction characterized by altered mental status, autonomic dysfunction, and neuromuscular abnormalities. It is most frequently caused by use of both serotonin reuptake inhibitors and monoamine oxidase inhibitors, leading to excess serotonin availability in the CNS at the serotonin 1A receptor.
A subclass of serotonin receptors that form cation channels and mediate signal transduction by depolarizing the cell membrane. The cation channels are formed from 5 receptor subunits. When stimulated the receptors allow the selective passage of SODIUM; POTASSIUM; and CALCIUM.
Drugs that bind to but do not activate SEROTONIN 5-HT1 RECEPTORS, thereby blocking the actions of SEROTONIN 5-HT1 RECEPTOR AGONISTS. Included under this heading are antagonists for one or more of the specific 5-HT1 receptor subtypes.
Endogenous compounds and drugs that specifically stimulate SEROTONIN 5-HT2 RECEPTORS. Included under this heading are agonists for one or more of the specific 5-HT2 receptor subtypes.
A subtype of G-protein-coupled SEROTONIN receptors that preferentially couple to GS STIMULATORY G-PROTEINS resulting in increased intracellular CYCLIC AMP. Several isoforms of the receptor exist due to ALTERNATIVE SPLICING of its mRNA.
Endogenous compounds and drugs that specifically stimulate SEROTONIN 5-HT1 RECEPTORS. Included under this heading are agonists for one or more of the specific 5-HT1 receptor subtypes.
An enzyme that catalyzes the hydroxylation of TRYPTOPHAN to 5-HYDROXYTRYPTOPHAN in the presence of NADPH and molecular oxygen. It is important in the biosynthesis of SEROTONIN.
Chemical substances which inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites.
Drugs that bind to but do not activate SEROTONIN 5-HT3 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN 5-HT3 RECEPTOR AGONISTS.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.
Drugs that bind to but do not activate DOPAMINE RECEPTORS, thereby blocking the actions of dopamine or exogenous agonists. Many drugs used in the treatment of psychotic disorders (ANTIPSYCHOTIC AGENTS) are dopamine antagonists, although their therapeutic effects may be due to long-term adjustments of the brain rather than to the acute effects of blocking dopamine receptors. Dopamine antagonists have been used for several other clinical purposes including as ANTIEMETICS, in the treatment of Tourette syndrome, and for hiccup. Dopamine receptor blockade is associated with NEUROLEPTIC MALIGNANT SYNDROME.
Compounds that inhibit or block the activity of NEUROKININ-1 RECEPTORS.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Agents inhibiting the effect of narcotics on the central nervous system.
Drugs that selectively bind to but do not activate histamine H2 receptors, thereby blocking the actions of histamine. Their clinically most important action is the inhibition of acid secretion in the treatment of gastrointestinal ulcers. Smooth muscle may also be affected. Some drugs in this class have strong effects in the central nervous system, but these actions are not well understood.
Hydroxyindoleacetic acid (5HIAA) is a major metabolite of serotonin, a neurotransmitter, formed by the action of monoamine oxidase and aldehyde dehydrogenase, and its measurement in urine is often used as a biomarker for serotonin synthesis in clinical and research settings.
A family of hexahydropyridines.
A ligand that binds to but fails to activate the INTERLEUKIN 1 RECEPTOR. It plays an inhibitory role in the regulation of INFLAMMATION and FEVER. Several isoforms of the protein exist due to multiple ALTERNATIVE SPLICING of its mRNA.
Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system.
The first highly specific serotonin uptake inhibitor. It is used as an antidepressant and often has a more acceptable side-effects profile than traditional antidepressants.
Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.
Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA.
A serotonin 1A-receptor agonist that is used experimentally to test the effects of serotonin.
Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.
The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant.
A furancarbonitrile that is one of the SEROTONIN UPTAKE INHIBITORS used as an antidepressant. The drug is also effective in reducing ethanol uptake in alcoholics and is used in depressed patients who also suffer from tardive dyskinesia in preference to tricyclic antidepressants, which aggravate this condition.
Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.
Neurons whose primary neurotransmitter is SEROTONIN.
Drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists. Classical antihistaminics block the histamine H1 receptors only.
Drugs that bind to nicotinic cholinergic receptors (RECEPTORS, NICOTINIC) and block the actions of acetylcholine or cholinergic agonists. Nicotinic antagonists block synaptic transmission at autonomic ganglia, the skeletal neuromuscular junction, and at central nervous system nicotinic synapses.
Drugs that bind to and block the activation of ADRENERGIC ALPHA-1 RECEPTORS.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS.
Compounds that bind to and block the stimulation of PURINERGIC P2 RECEPTORS.
A serotonin uptake inhibitor that is effective in the treatment of depression.
A selective and irreversible inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the biosynthesis of serotonin (5-HYDROXYTRYPTAMINE). Fenclonine acts pharmacologically to deplete endogenous levels of serotonin.
Piperazines are a class of heterocyclic organic compounds containing a seven-membered ring with two nitrogen atoms at positions 1 and 4, often used in pharmaceuticals as smooth muscle relaxants, antipsychotics, antidepressants, and antihistamines, but can also be found as recreational drugs with stimulant and entactogen properties.
A serotonin receptor subtype that is localized to the CAUDATE NUCLEUS; PUTAMEN; the NUCLEUS ACCUMBENS; the HIPPOCAMPUS, and the RAPHE NUCLEI. It plays a role as a terminal autoreceptor that regulates the rate of SEROTONIN release from nerve endings. This serotonin receptor subtype is closely related to and has similar drug binding properties as the 5-HT1B RECEPTOR, but is expressed at low levels. It is particularly sensitive to the agonist SUMATRIPTAN and may be involved in mediating the drug's antimigrane effect.
One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.
The observable response an animal makes to any situation.
Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).
Drugs that bind to and block the activation of ADRENERGIC ALPHA-2 RECEPTORS.
Tryptamine substituted with two hydroxyl groups in positions 5 and 7. It is a neurotoxic serotonin analog that destroys serotonergic neurons preferentially and is used in neuropharmacology as a tool.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS.
A class of drugs designed to prevent leukotriene synthesis or activity by blocking binding at the receptor level.
Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.
Agents that antagonize ANGIOTENSIN RECEPTORS. Many drugs in this class specifically target the ANGIOTENSIN TYPE 1 RECEPTOR.
Drugs that bind to but do not activate ADRENERGIC RECEPTORS. Adrenergic antagonists block the actions of the endogenous adrenergic transmitters EPINEPHRINE and NOREPINEPHRINE.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
The action of a drug that may affect the activity, metabolism, or toxicity of another drug.
Biogenic amines having only one amine moiety. Included in this group are all natural monoamines formed by the enzymatic decarboxylation of natural amino acids.
Drugs that bind to but do not activate GABA-A RECEPTORS thereby blocking the actions of endogenous or exogenous GABA-A RECEPTOR AGONISTS.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Mood-stimulating drugs used primarily in the treatment of affective disorders and related conditions. Several MONOAMINE OXIDASE INHIBITORS are useful as antidepressants apparently as a long-term consequence of their modulation of catecholamine levels. The tricyclic compounds useful as antidepressive agents (ANTIDEPRESSIVE AGENTS, TRICYCLIC) also appear to act through brain catecholamine systems. A third group (ANTIDEPRESSIVE AGENTS, SECOND-GENERATION) is a diverse group of drugs including some that act specifically on serotonergic systems.
Drugs that bind to but do not activate SEROTONIN 5-HT4 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN RECEPTOR AGONISTS.
Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
A selective and potent serotonin-2 antagonist that is effective in the treatment of a variety of syndromes related to anxiety and depression. The drug also improves the subjective quality of sleep and decreases portal pressure.
Elements of limited time intervals, contributing to particular results or situations.
Decarboxylated monoamine derivatives of TRYPTOPHAN.
Drugs that selectively bind to but do not activate HISTAMINE H3 RECEPTORS. They have been used to correct SLEEP WAKE DISORDERS and MEMORY DISORDERS.

Role of dexamethasone dosage in combination with 5-HT3 antagonists for prophylaxis of acute chemotherapy-induced nausea and vomiting. (1/2067)

Dexamethasone (20 mg) or its equivalent in combination with 5-HT3 antagonists appears to be the gold-standard dose for antiemetic prophylaxis. Additional to concerns about the use of corticosteroids with respect to enhanced tumour growth or impaired killing of the tumour cells, there is evidence that high-dosage dexamethasone impairs the control of delayed nausea and emesis, whereas lower doses appear more beneficial. To come closer to the most adequate dose, we started a prospective, single-blind, randomized trial investigating additional dosage of 8 or 20 mg dexamethasone to tropisetron (Navoban), a 5-HT3 receptor antagonist, in cis-platinum-containing chemotherapy. After an interim analysis of 121 courses of chemotherapy in 69 patients, we have been unable to detect major differences between both treatment alternatives. High-dose dexamethasone (20 mg) had no advantage over medium-dose dexamethasone with respect to objective and subjective parameters of acute and delayed nausea and vomiting. In relation to concerns about the use of corticosteroids in non-haematological cancer chemotherapy, we suggest that 8 mg or its equivalent should be used in combination with 5-HT3 antagonists until further research proves otherwise.  (+info)

S-16924 [(R)-2-[1-[2-(2,3-dihydro-benzo[1,4]dioxin-5-yloxy)-ethyl]- pyrrolidin-3yl]-1-(4-fluorophenyl)-ethanone], a novel, potential antipsychotic with marked serotonin1A agonist properties: III. Anxiolytic actions in comparison with clozapine and haloperidol. (2/2067)

S-16924 is a potential antipsychotic that displays agonist and antagonist properties at serotonin (5-HT)1A and 5-HT2A/2C receptors, respectively. In a pigeon conflict procedure, the benzodiazepine clorazepate (CLZ) increased punished responses, an action mimicked by S-16924, whereas the atypical antipsychotic clozapine and the neuroleptic haloperidol were inactive. Similarly, in a Vogel conflict paradigm in rats, CLZ increased punished responses, an action shared by S-16924 but not by clozapine or haloperidol. This action of S-16924 was abolished by the 5-HT1A antagonist WAY-100,635. Ultrasonic vocalizations in rats were inhibited by CLZ, S-16924, clozapine, and haloperidol. However, although WAY-100,635 abolished the action of S-16924, it did not affect clozapine and haloperidol. In a rat elevated plus-maze, CLZ, but not S-16924, clozapine, and haloperidol, increased open-arm entries. Like CLZ, S-16924 increased social interaction in rats, whereas clozapine and haloperidol were inactive. WAY-100,635 abolished this action of S-16924. CLZ, S-16924, clozapine, and haloperidol decreased aggressive interactions in isolated mice, but this effect of S-16924 was not blocked by WAY-100, 635. All drugs inhibited motor behavior, but the separation to anxiolytic doses was more pronounced for S-16924 than for CLZ. Finally, in freely moving rats, CLZ and S-16924, but not clozapine and haloperidol, decreased dialysis levels of 5-HT in the nucleus accumbens: this action of S-16924 was blocked by WAY-100,165. In conclusion, in contrast to haloperidol and clozapine, S-16924 possessed a broad-based profile of anxiolytic activity at doses lower than those provoking motor disruption. Its principal mechanism of action was activation of 5-HT1A (auto)receptors.  (+info)

Intestinal prokinesia by two esters of 4-amino-5-chloro-2- methoxybenzoic acid: involvement of 5-hydroxytryptamine-4 receptors and dissociation from cardiac effects in vivo. (3/2067)

In five fasting, conscious dogs, we compared the prokinetic action of two selective 5-hydroxytryptamine-4 (5-HT4) receptor agonists with low affinity for 5-HT3 receptors ML10302 (2-piperidinoethyl 4-amino-5-chloro-2-methoxybenzoate) and SR59768 (2-[(3S)-3-hydroxypiperidino]ethyl 4-amino-5-chloro-2-methoxybenzoate) in the duodenum and jejunum, using cisapride as a reference compound. Heart rate and rate-corrected QT (QTc) also were monitored to assess whether or not the cardiac effects of cisapride are shared by other 5-HT4 receptor agonists. Both ML10302 and SR59768 dose-dependently stimulated spike activity in the duodenum with similar potencies (dose range, 3-300 nmol/kg i.v.; ED50 values: 24 and 23 nmol/kg i.v., respectively), mimicking the effect of cisapride (30-3000 nmol/kg i.v.). The maximal effect was achieved with the dose of 100 nmol/kg i.v. for both compounds. Similar findings were obtained in the jejunum. Atropine and GR125487 (1-[2-[(methylsulfonyl)amino]ethyl]-4-piperidinyl-methyl 5-fluoro-2-methoxy-1H-indole-3-carboxylate, selective 5-HT4 receptor antagonist), at doses having no effect per se, antagonized intestinal prokinesia by maximal doses of ML10302 and SR59768. Neither ML10302 nor SR59768 had any effect on heart rate or QTc at any of the doses tested, whereas cisapride, at the highest dose (3000 nmol/kg), induced tachycardia and lengthened the QTC (p <.01). In conclusion, ML10302 and SR59768 share with cisapride a similar prokinetic action in the canine duodenum and jejunum in vivo. This effect is mediated by pathways involving activation of 5-HT4 and muscarinic receptors. Unlike cisapride, which induces tachycardia and prolongs the QTc by a mechanism probably unrelated to 5-HT4 receptor activation, ML10302 and SR59768 are devoid of cardiac effects in this model.  (+info)

Selective antiaggressive effects of alnespirone in resident-intruder test are mediated via 5-hydroxytryptamine1A receptors: A comparative pharmacological study with 8-hydroxy-2-dipropylaminotetralin, ipsapirone, buspirone, eltoprazine, and WAY-100635. (4/2067)

The present study characterized the effects of the novel, selective, and potent 5-hydroxytryptamine1A (serotonin) (5-HT1A) receptor agonist, alnespirone [S-20499, (S)-N-4-[5-methoxychroman-3-yl)propylamino)butyl- 8-azaspiro-(4,5)-diacetamide, hydrochloride] on offensive and defensive resident-intruder aggression in wild-type rats and compared its actions with those of the prototypical full 5-HT1A agonist 8-hydroxy-2- dipropylaminotetralin (8-OH-DPAT), the partial 5-HT1A agonists ipsapirone and buspirone, and the mixed 5-HT1A/1B agonist eltoprazine. All five agonists exerted effective dose-dependent decreases of offensive aggressive behavior in resident rats; 8-OH-DPAT was the most potent (ID50 = 0.074 mg/kg), followed by eltoprazine (0.24), buspirone (0.72), ipsapirone (1.08), and alnespirone (1.24). However, in terms of selectivity of the antiaggressive effects as determined by the absence of decrements in social interest and general motor activity, alnespirone appeared to be superior. In the defensive aggression test, neither alnespirone nor any of the other four agonists changed defensive behaviors in the intruder rats. The involvement of 5-HT1A receptors in the antiaggressive actions of these drugs was confirmed by showing that the selective 5-HT1A receptor antagonist WAY-100635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2- pyridinyl)cyclohexanecarboxamide trihydrochloride), which was inactive alone, fully prevented the antiaggressive effects of alnespirone, 8-OH-DPAT, and buspirone and partly reversed those of ipsapirone and eltoprazine. The data clearly indicate that alnespirone effectively suppresses offensive aggression with an advantageous profile of action compared with other full or partial 5-HT1A agonists. These selective antiaggressive actions of alnespirone are mediated by stimulating 5-HT1A receptors, presumably the somatodendritic autoreceptors at the raphe nuclei. Furthermore, the data provide evidence for a major involvement of these 5-HT1A receptors in the modulation of aggressive behavior by 8-OH-DPAT, ipsapirone, buspirone, and eltoprazine.  (+info)

[3H]-Mesulergine labels 5-HT7 sites in rat brain and guinea-pig ileum but not rat jejunum. (5/2067)

1. The primary aim of this investigation was to determine whether binding sites corresponding to the 5-HT7 receptor could be detected in smooth muscle of the rat jejunum. Binding studies in rat brain (whole brain minus cerebellum) and guinea-pig ileal longitudinal muscle were also undertaken in order to compare the binding characteristics of these tissues. Studies were performed using [3H]-mesulergine, as it has a high affinity for 5-HT7 receptors. 2. In the rat brain and guinea-pig ileum, pKD values for [3H]-mesulergine of 8.0 +/- 0.04 and 7.9 +/- 0.11 (n = 3) and Bmax values of 9.9 +/- 0.3 and 21.5 +/- 4.9 fmol mg(-1) protein were obtained respectively, but no binding was detected in the rat jejunum. [3H]-mesulergine binding in the rat brain and guinea-pig ileum was displaced with the agonists 5-carboxamidotryptamine (5-CT) > 5-hydroxytryptamine (5-HT) > or = 5-methoxytryptamine (5-MeOT) > sumatriptan and the antagonists risperidone > or = LSD > or = metergoline > ritanserin > > pindolol. 3. Despite the lack of [3H]-mesulergine binding in the rat jejunum, functional studies undertaken revealed a biphasic contractile response to 5-HT which was partly blocked by ondansetron (1 microM). The residual response was present in over 50% of tissues studied and was found to be inhibited by risperidone > LSD > metergoline > mesulergine = ritanserin > pindolol, but was unaffected by RS 102221 (3 microM), cinanserin (30 nM), yohimbine (0.1 microM) and GR 113808 (1 microM). In addition, the agonist order of potency was 5-CT > 5-HT > 5-MeOT > sumatriptan. 4. In conclusion, binding studies performed with [3H]-mesulergine were able to detect 5-HT7 sites in rat brain and guinea-pig ileum, but not in rat jejunum, where a functional 5-HT7-like receptor was present.  (+info)

5-HT2B-receptor antagonist LY-272015 is antihypertensive in DOCA-salt-hypertensive rats. (6/2067)

We previously demonstrated a change in the receptors mediating 5-hydroxytryptamine (5-HT)-induced contraction in arteries of deoxycorticosterone acetate (DOCA)-salt-hypertensive rats. Specifically, contraction to 5-HT is mediated primarily by 5-HT2A receptors in arteries from normotensive sham rats and by both 5-HT2A and 5-HT2B receptors in arteries from hypertensive rats. We hypothesized that the 5-HT2B receptor may play a role in maintaining the high blood pressure of DOCA-salt-hypertensive rats, and herein we provide data connecting in vitro and in vivo findings. The endothelium-denuded isolated superior mesenteric artery of DOCA-salt rats displayed a marked increase in maximum contraction to the newly available 5-HT2B-receptor agonist BW-723C86 compared with that of arteries from sham rats, confirming that the 5-HT2B receptor plays a greater role in 5-HT-induced contraction in arteries from DOCA-salt rats. In chronically instrumented rats, the 5-HT2B-receptor antagonist LY-272015 (0.3, 1.0, and 3.0 mg/kg iv at 30-min intervals) was given cumulatively 1 time/wk during 4 wk of continued DOCA-salt treatment. LY-272015 did not reduce blood pressure of the sham-treated rats at any time or dose. However, LY-272015 (1.0 and 3. 0 mg/kg) significantly reduced mean blood pressure in a subgroup of week 3 (-20 mmHg) and week 4 DOCA-salt (-40 mmHg) rats that had extremely high blood pressure (mean arterial blood pressure approximately 200 mmHg). Blockade of 5-HT2B receptors by in vivo administration of LY-272015 (3.0 mg/kg) was verified by observing reduced 5-HT-induced contraction in rat stomach fundus, the tissue from which the 5-HT2B receptor was originally cloned. These data support the novel hypothesis that 5-HT2B-receptor expression is induced during the development of DOCA-salt hypertension and contributes to the maintenance of severe blood pressure elevations.  (+info)

Effect of 5-HT4 receptor stimulation on the pacemaker current I(f) in human isolated atrial myocytes. (7/2067)

OBJECTIVE: 5-HT4 receptors are present in human atrial cells and their stimulation has been implicated in the genesis of atrial arrhythmias including atrial fibrillation. An I(f)-like current has been recorded in human atrial myocytes, where it is modulated by beta-adrenergic stimulation. In the present study, we investigated the effect of serotonin (5-hydroxytryptamine, 5-HT) on I(f) electrophysiological properties, in order to get an insight into the possible contribution of I(f) to the arrhythmogenic action of 5-HT in human atria. METHODS: Human atrial myocytes were isolated by enzymatic digestion from samples of atrial appendage of patients undergoing coeffective cardiac surgery. Patch-clamped cells were superfused with a modified Tyrode's solution in order to amplify I(f) and reduce overlapping currents. RESULTS AND CONCLUSIONS: A time-dependent, cesium-sensitive increasing inward current, that we had previously described having the electrophysiological properties of the pacemaker current I(f), was elicited by negative steps (-60 to -130 mV) from a holding potential of -40 mV. Boltzmann fit of control activation curves gave a midpoint (V1/2) of -88.9 +/- 2.6 mV (n = 14). 5-HT (1 microM) consistently caused a positive shift of V1/2 of 11.0 +/- 2.0 mV (n = 8, p < 0.001) of the activation curve toward less negative potentials, thus increasing the amount of current activated by clamp steps near the physiological maximum diastolic potential of these cells. The effect was dose-dependent, the EC50 being 0.14 microM. Maximum current amplitude was not changed by 5-HT. 5-HT did not increase I(f) amplitude when the current was maximally activated by cAMP perfused into the cell. The selective 5-HT4 antagonists, DAU 6285 (10 microM) and GR 125487 (1 microM), completely prevented the effect of 5-HT on I(f). The shift of V1/2 caused by 1 microM 5-HT in the presence of DAU 6285 or GR 125487 was 0.3 +/- 1 mV (n = 6) and 1.0 +/- 0.6 mV (n = 5), respectively (p < 0.01 versus 5-HT alone). The effect of 5-HT4 receptor blockade was specific, since neither DAU 6285 nor GR 125487 prevented the effect of 1 microM isoprenaline on I(f). Thus, 5-HT4 stimulation increases I(f) in human atrial myocytes; this effect may contribute to the arrhythmogenic action of 5-HT in human atrium.  (+info)

Vasoconstriction in human isolated middle meningeal arteries: determining the contribution of 5-HT1B- and 5-HT1F-receptor activation. (8/2067)

AIMS: Sumatriptan is a 5-HT1B/1D-receptor agonist which also has affinity for 5-HT1F-receptors. The vasoconstrictor effects of sumatriptan are thought to be 5-HT1B-receptor mediated and these receptors have been shown to be expressed in human cranial blood vessels. However, in the same tissue mRNA coding for 5-HT1F-receptors has also been identified and this study addresses the possibility of whether 5-HT1F-receptor activation contributes to vasoconstriction. METHODS: The ability of two selective 5-HT1B/1D-receptor antagonists (GR125,743 and GR127,935) with no affinity for 5-HT1F-receptors, to inhibit sumatriptan evoked contractions in human isolated middle meningeal artery was investigated. Using a series of 5-HT1B/1D-receptor agonists (sumatriptan, zolmitriptan, CP122,288, L-741,519 and L-741,604), some with high affinity for 5-HTIF-receptors and the non-selective 5-HT-receptor agonists 5-HT and 5-CT, we compared the vasoconstrictor potency of these drugs in human isolated middle meningeal artery with their affinities at cloned human 5-HT1B-, 5-HT1D-and 5-HT1F-receptors expressed in CHO cell lines. RESULTS: GR125,743 antagonized sumatriptan evoked contractions in a competitive manner (apparent pA2 9.1) and GR127,935 antagonized sumatriptan-induced responses in a non-competitive manner (reducing the maximum contraction to 27%). There was a significant correlation between vasoconstrictor potency and 5-HT1B-receptor affinity (r=0.93, P=0.002) but not with 5-HT1D- or 5-HT1F-receptor affinity (r=0.74, P=0.06; r= 0.31, P= 0.49, respectively). CONCLUSIONS: These experiments show that in human middle meningeal artery vasoconstriction to sumatriptan-like agents is 5-HT1B-receptor mediated with little if any contribution from 5-HT1F-receptor activation.  (+info)

Serotonin antagonists are a class of drugs that block the action of serotonin, a neurotransmitter, at specific receptor sites in the brain and elsewhere in the body. They work by binding to the serotonin receptors without activating them, thereby preventing the natural serotonin from binding and transmitting signals.

Serotonin antagonists are used in the treatment of various conditions such as psychiatric disorders, migraines, and nausea and vomiting associated with cancer chemotherapy. They can have varying degrees of affinity for different types of serotonin receptors (e.g., 5-HT2A, 5-HT3, etc.), which contributes to their specific therapeutic effects and side effect profiles.

Examples of serotonin antagonists include ondansetron (used to treat nausea and vomiting), risperidone and olanzapine (used to treat psychiatric disorders), and methysergide (used to prevent migraines). It's important to note that these medications should be used under the supervision of a healthcare provider, as they can have potential risks and interactions with other drugs.

Cyproheptadine is an antihistamine and anticholinergic medication that is primarily used to treat symptoms of allergies, such as runny nose, sneezing, and itching. It works by blocking the action of histamine, a substance in the body that causes allergic reactions.

Cyproheptadine also has other uses, including the treatment of migraines and cluster headaches, appetite stimulation in people with certain medical conditions, and as a sedative in some cases. It is available in various forms, such as tablets, capsules, and syrup.

Like all medications, cyproheptadine can have side effects, including drowsiness, dry mouth, dizziness, and blurred vision. It is important to follow the dosage instructions carefully and talk to a healthcare provider if you experience any bothersome or persistent side effects.

Methysergide is a medication that belongs to a class of drugs called ergot alkaloids. It is primarily used for the prophylaxis (prevention) of migraine headaches. Methysergide works by narrowing blood vessels around the brain, which is thought to help prevent migraines.

The medical definition of Methysergide is:
A semisynthetic ergot alkaloid derivative used in the prophylaxis of migraine and cluster headaches. It has both agonist and antagonist properties at serotonin receptors, and its therapeutic effects are thought to be related to its ability to block the binding of serotonin to its receptors. However, methysergide can have serious side effects, including fibrotic reactions in various organs, such as the heart, lungs, and kidneys, so it is usually used only for short periods of time and under close medical supervision.

Serotonin, also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter that is found primarily in the gastrointestinal (GI) tract, blood platelets, and the central nervous system (CNS) of humans and other animals. It is produced by the conversion of the amino acid tryptophan to 5-hydroxytryptophan (5-HTP), and then to serotonin.

In the CNS, serotonin plays a role in regulating mood, appetite, sleep, memory, learning, and behavior, among other functions. It also acts as a vasoconstrictor, helping to regulate blood flow and blood pressure. In the GI tract, it is involved in peristalsis, the contraction and relaxation of muscles that moves food through the digestive system.

Serotonin is synthesized and stored in serotonergic neurons, which are nerve cells that use serotonin as their primary neurotransmitter. These neurons are found throughout the brain and spinal cord, and they communicate with other neurons by releasing serotonin into the synapse, the small gap between two neurons.

Abnormal levels of serotonin have been linked to a variety of disorders, including depression, anxiety, schizophrenia, and migraines. Medications that affect serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs), are commonly used to treat these conditions.

Ketanserin is a medication that belongs to a class of drugs called serotonin antagonists. It works by blocking the action of serotonin, a neurotransmitter in the brain, on certain types of receptors. Ketanserin is primarily used for its blood pressure-lowering effects and is also sometimes used off-label to treat anxiety disorders and alcohol withdrawal syndrome.

It's important to note that ketanserin is not approved by the FDA for use in the United States, but it may be available in other countries as a prescription medication. As with any medication, ketanserin should only be used under the supervision of a healthcare provider and should be taken exactly as prescribed.

Ondansetron is a medication that is primarily used to prevent nausea and vomiting caused by chemotherapy, radiation therapy, or surgery. It is a selective antagonist of 5-HT3 receptors, which are found in the brain and gut and play a role in triggering the vomiting reflex. By blocking these receptors, ondansetron helps to reduce the frequency and severity of nausea and vomiting.

The drug is available in various forms, including tablets, oral solution, and injection, and is typically administered 30 minutes before chemotherapy or surgery, and then every 8 to 12 hours as needed. Common side effects of ondansetron include headache, constipation, and diarrhea.

It's important to note that ondansetron should be used under the supervision of a healthcare provider, and its use may be contraindicated in certain individuals, such as those with a history of allergic reactions to the drug or who have certain heart conditions.

Antiemetics are a class of medications that are used to prevent and treat nausea and vomiting. They work by blocking or reducing the activity of dopamine, serotonin, and other neurotransmitters in the brain that can trigger these symptoms. Antiemetics can be prescribed for a variety of conditions, including motion sickness, chemotherapy-induced nausea and vomiting, postoperative nausea and vomiting, and pregnancy-related morning sickness. Some common examples of antiemetic medications include ondansetron (Zofran), promethazine (Phenergan), and metoclopramide (Reglan).

Nausea is a subjective, unpleasant sensation of discomfort in the stomach and upper gastrointestinal tract that may precede vomiting. It's often described as a feeling of queasiness or the need to vomit. Nausea can be caused by various factors, including motion sickness, pregnancy, gastrointestinal disorders, infections, certain medications, and emotional stress. While nausea is not a disease itself, it can be a symptom of an underlying medical condition that requires attention and treatment.

Vomiting is defined in medical terms as the forceful expulsion of stomach contents through the mouth. It is a violent, involuntary act that is usually accompanied by strong contractions of the abdominal muscles and retching. The body's vomiting reflex is typically triggered when the brain receives signals from the digestive system that something is amiss.

There are many potential causes of vomiting, including gastrointestinal infections, food poisoning, motion sickness, pregnancy, alcohol consumption, and certain medications or medical conditions. In some cases, vomiting can be a symptom of a more serious underlying condition, such as a brain injury, concussion, or chemical imbalance in the body.

Vomiting is generally not considered a serious medical emergency on its own, but it can lead to dehydration and other complications if left untreated. If vomiting persists for an extended period of time, or if it is accompanied by other concerning symptoms such as severe abdominal pain, fever, or difficulty breathing, it is important to seek medical attention promptly.

Serotonin receptors are a type of cell surface receptor that bind to the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). They are widely distributed throughout the body, including the central and peripheral nervous systems, where they play important roles in regulating various physiological processes such as mood, appetite, sleep, memory, learning, and cognition.

There are seven different classes of serotonin receptors (5-HT1 to 5-HT7), each with multiple subtypes, that exhibit distinct pharmacological properties and signaling mechanisms. These receptors are G protein-coupled receptors (GPCRs) or ligand-gated ion channels, which activate intracellular signaling pathways upon serotonin binding.

Serotonin receptors have been implicated in various neurological and psychiatric disorders, including depression, anxiety, schizophrenia, and migraine. Therefore, selective serotonin receptor agonists or antagonists are used as therapeutic agents for the treatment of these conditions.

Serotonin plasma membrane transport proteins, also known as serotonin transporters (SERTs), are membrane-spanning proteins that play a crucial role in the regulation of serotonergic neurotransmission. They are responsible for the reuptake of serotonin (5-hydroxytryptamine or 5-HT) from the synaptic cleft back into the presynaptic neuron, thereby terminating the signal transmission and allowing for its recycling or degradation.

Structurally, SERTs belong to the family of sodium- and chloride-dependent neurotransmitter transporters and contain 12 transmembrane domains with intracellular N- and C-termini. The binding site for serotonin is located within the transmembrane domain, while the substrate-binding site is formed by residues from both the transmembrane and extracellular loops.

Serotonin transporters are important targets for various psychotropic medications, including selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs). These drugs act by blocking the SERT, increasing synaptic concentrations of serotonin, and enhancing serotonergic neurotransmission. Dysregulation of serotonin transporters has been implicated in several neurological and psychiatric disorders, such as major depressive disorder, anxiety disorders, obsessive-compulsive disorder, and substance abuse.

A serotonin receptor, specifically the 5-HT2A subtype (5-hydroxytryptamine 2A receptor), is a type of G protein-coupled receptor found in the cell membrane. It is activated by the neurotransmitter serotonin and plays a role in regulating various physiological processes, including mood, cognition, sleep, and sensory perception.

The 5-HT2A receptor is widely distributed throughout the central nervous system and has been implicated in several neurological and psychiatric disorders, such as depression, anxiety, schizophrenia, and migraine. It is also the primary target of several psychoactive drugs, including hallucinogens like LSD and psilocybin, as well as atypical antipsychotics used to treat conditions like schizophrenia.

The 5-HT2A receptor signals through a G protein called Gq, which activates a signaling cascade that ultimately leads to the activation of phospholipase C and the production of second messengers such as inositol trisphosphate (IP3) and diacylglycerol (DAG). These second messengers then go on to modulate various cellular processes, including the release of neurotransmitters and the regulation of gene expression.

A serotonin receptor, specifically the 5-HT1A subtype, is a type of G protein-coupled receptor found in the central and peripheral nervous systems. These receptors are activated by the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT) and play important roles in regulating various physiological processes, including neurotransmission, neuronal excitability, and neuroendocrine function.

The 5-HT1A receptor is widely distributed throughout the brain and spinal cord, where it is involved in modulating mood, anxiety, cognition, memory, and pain perception. Activation of this receptor can have both inhibitory and excitatory effects on neuronal activity, depending on the location and type of neuron involved.

In addition to its role in normal physiology, the 5-HT1A receptor has been implicated in various pathological conditions, including depression, anxiety disorders, schizophrenia, and drug addiction. As a result, drugs that target this receptor have been developed for the treatment of these conditions. These drugs include selective serotonin reuptake inhibitors (SSRIs), which increase the availability of serotonin in the synaptic cleft and enhance 5-HT1A receptor activation, as well as direct agonists of the 5-HT1A receptor, such as buspirone, which is used to treat anxiety disorders.

Serotonin uptake inhibitors (also known as Selective Serotonin Reuptake Inhibitors or SSRIs) are a class of medications primarily used to treat depression and anxiety disorders. They work by increasing the levels of serotonin, a neurotransmitter in the brain that helps regulate mood, appetite, and sleep, among other functions.

SSRIs block the reuptake of serotonin into the presynaptic neuron, allowing more serotonin to be available in the synapse (the space between two neurons) for binding to postsynaptic receptors. This results in increased serotonergic neurotransmission and improved mood regulation.

Examples of SSRIs include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), and escitalopram (Lexapro). These medications are generally well-tolerated, with side effects that may include nausea, headache, insomnia, sexual dysfunction, and increased anxiety or agitation. However, they can have serious interactions with other medications, so it is important to inform your healthcare provider of all medications you are taking before starting an SSRI.

A serotonin receptor, specifically the 5-HT2C (5-hydroxytryptamine 2C) receptor, is a type of G protein-coupled receptor found in the central and peripheral nervous systems. These receptors are activated by the neurotransmitter serotonin (also known as 5-hydroxytryptamine or 5-HT) and play crucial roles in various physiological processes, including mood regulation, appetite control, sleep, and memory.

The 5-HT2C receptor is primarily located on postsynaptic neurons and can also be found on presynaptic terminals. When serotonin binds to the 5-HT2C receptor, it triggers a signaling cascade that ultimately influences the electrical activity of the neuron. This receptor has been associated with several neurological and psychiatric conditions, such as depression, anxiety, schizophrenia, and eating disorders.

Pharmacological agents targeting the 5-HT2C receptor have been developed for the treatment of various diseases. For example, some antipsychotic drugs work as antagonists at this receptor to alleviate positive symptoms of schizophrenia. Additionally, agonists at the 5-HT2C receptor have shown potential in treating obesity due to their anorexigenic effects. However, further research is needed to fully understand the therapeutic and side effects of these compounds.

Serotonin receptor agonists are a class of medications that bind to and activate serotonin receptors in the body, mimicking the effects of the neurotransmitter serotonin. These drugs can have various effects depending on which specific serotonin receptors they act upon. Some serotonin receptor agonists are used to treat conditions such as migraines, cluster headaches, and Parkinson's disease, while others may be used to stimulate appetite or reduce anxiety. It is important to note that some serotonin receptor agonists can have serious side effects, particularly when taken in combination with other medications that affect serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors (MAOIs). This can lead to a condition called serotonin syndrome, which is characterized by symptoms such as agitation, confusion, rapid heart rate, high blood pressure, and muscle stiffness.

A serotonin receptor, specifically the 5-HT2B receptor, is a type of G protein-coupled receptor (GPCR) that binds to the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT). These receptors are located on the cell membrane of certain cells, including neurons and other cell types in various organs.

The 5-HT2B receptor is involved in a variety of physiological functions, such as regulating mood, appetite, sleep, and sensory perception. In the cardiovascular system, activation of 5-HT2B receptors can lead to the proliferation of cardiac fibroblasts and changes in the extracellular matrix, which may contribute to heart valve abnormalities.

In the central nervous system, 5-HT2B receptors have been implicated in several neurological conditions, including migraine, depression, and schizophrenia. However, their precise roles in these disorders are not yet fully understood.

Pharmacologically targeting 5-HT2B receptors has led to the development of drugs for various indications, such as antimigraine medications (e.g., telcagepant) and potential treatments for heart failure (e.g., mavacamten). However, some 5-HT2B receptor agonists have also been associated with serious side effects, such as valvular heart disease, which has limited their clinical use.

Serotonin 5-HT2 receptor antagonists are a class of drugs that block the action of serotonin, a neurotransmitter, at 5-HT2 receptors. These receptors are found in the central and peripheral nervous systems and are involved in various physiological functions such as mood regulation, cognition, appetite control, and vasoconstriction.

By blocking the action of serotonin at these receptors, serotonin 5-HT2 receptor antagonists can produce a range of effects depending on the specific receptor subtype that they target. For example, some serotonin 5-HT2 receptor antagonists are used to treat psychiatric disorders such as schizophrenia and depression, while others are used to treat migraines or prevent nausea and vomiting associated with chemotherapy.

Some common examples of serotonin 5-HT2 receptor antagonists include risperidone, olanzapine, and paliperidone (used for the treatment of schizophrenia), mirtazapine (used for the treatment of depression), sumatriptan (used for the treatment of migraines), and ondansetron (used to prevent nausea and vomiting).

'Receptors, Serotonin, 5-HT2' refer to a specific family of serotonin receptors that are activated by the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT). These receptors are G protein-coupled receptors and are further divided into several subtypes, including 5-HT2A, 5-HT2B, and 5-HT2C. They are widely distributed throughout the body, including the central nervous system, cardiovascular system, gastrointestinal tract, and respiratory system.

The 5-HT2 receptors play a role in various physiological processes, such as neurotransmission, vasoconstriction, smooth muscle contraction, and cell growth regulation. They are also involved in several pathophysiological conditions, including psychiatric disorders (e.g., depression, anxiety, schizophrenia), migraine, cardiovascular diseases, and pulmonary hypertension.

The 5-HT2 receptors have been a focus of drug development for various therapeutic areas. For example, atypical antipsychotics used to treat schizophrenia work by blocking the 5-HT2A receptor, while certain migraine medications act as agonists at the 5-HT1B/1D and 5-HT2C receptors. However, drugs targeting these receptors must be carefully designed to avoid unwanted side effects, as activation or blockade of these receptors can have significant impacts on various physiological processes.

A serotonin receptor, specifically the 5-HT1B receptor, is a type of G protein-coupled receptor found in the cell membrane. It binds to the neurotransmitter serotonin (also known as 5-hydroxytryptamine or 5-HT) and plays a role in regulating various physiological functions, including neurotransmission, vasoconstriction, and smooth muscle contraction.

The 5-HT1B receptor is widely distributed throughout the body, but it is particularly abundant in the brain, where it is involved in modulating mood, cognition, and motor control. When serotonin binds to the 5-HT1B receptor, it activates a signaling pathway that ultimately leads to the inhibition of adenylyl cyclase, which reduces the production of cAMP (cyclic adenosine monophosphate) in the cell. This reduction in cAMP levels can have various effects on cellular function, depending on the specific tissue and context in which the 5-HT1B receptor is expressed.

In addition to its role as a serotonin receptor, the 5-HT1B receptor has also been identified as a target for certain drugs used in the treatment of migraine headaches, such as triptans. These medications bind to and activate the 5-HT1B receptor, which leads to vasoconstriction of cranial blood vessels and inhibition of neuropeptide release, helping to alleviate the symptoms of migraines.

Serotonin agents are a class of drugs that work on the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) in the brain and elsewhere in the body. They include several types of medications such as:

1. Selective Serotonin Reuptake Inhibitors (SSRIs): These drugs block the reabsorption (reuptake) of serotonin into the presynaptic neuron, increasing the availability of serotonin in the synapse to interact with postsynaptic receptors. SSRIs are commonly used as antidepressants and include medications such as fluoxetine, sertraline, and citalopram.
2. Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs): These drugs block the reabsorption of both serotonin and norepinephrine into the presynaptic neuron, increasing the availability of these neurotransmitters in the synapse. SNRIs are also used as antidepressants and include medications such as venlafaxine and duloxetine.
3. Serotonin Receptor Agonists: These drugs bind to and activate serotonin receptors, mimicking the effects of serotonin. They are used for various indications, including migraine prevention (e.g., sumatriptan) and Parkinson's disease (e.g., pramipexole).
4. Serotonin Receptor Antagonists: These drugs block serotonin receptors, preventing the effects of serotonin. They are used for various indications, including nausea and vomiting (e.g., ondansetron) and as mood stabilizers in bipolar disorder (e.g., olanzapine).
5. Serotonin Synthesis Inhibitors: These drugs block the enzymatic synthesis of serotonin, reducing its availability in the brain. They are used as antidepressants and include medications such as monoamine oxidase inhibitors (MAOIs) like phenelzine and tranylcypromine.

It's important to note that while these drugs all affect serotonin, they have different mechanisms of action and are used for various indications. It's essential to consult a healthcare professional before starting any new medication.

'Receptors, Serotonin, 5-HT1' refer to a class of serotonin receptors that are activated by the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT) and coupled to G proteins. These receptors play a role in regulating various physiological processes, including neurotransmission, vasoconstriction, and smooth muscle contraction. The 5-HT1 receptor family includes several subtypes (5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, and 5-HT1F) that differ in their distribution, function, and signaling mechanisms. These receptors are important targets for the treatment of various neurological and psychiatric disorders, such as depression, anxiety, migraine, and schizophrenia.

Serotonin syndrome is a potentially life-threatening condition that arises from excessive serotonergic activity in the central nervous system (CNS) and peripheral nervous system. It is typically caused by the interaction of medications, illicit substances, or dietary supplements that increase serotonin levels or enhance serotonin receptor sensitivity.

The diagnostic criteria for serotonin syndrome include:

1. Presence of a serotonergic medication or drug known to cause the syndrome
2. Development of neuromuscular abnormalities, such as hyperreflexia, myoclonus, tremor, rigidity, or akathisia
3. Autonomic dysfunction, including diaphoresis, tachycardia, hypertension, dilated pupils, and hyperthermia
4. Mental status changes, such as agitation, confusion, hallucinations, or coma
5. Symptoms that develop rapidly, usually within hours of a change in serotonergic medication or dosage

Serotonin syndrome can range from mild to severe, with the most severe cases potentially leading to respiratory failure, rhabdomyolysis, disseminated intravascular coagulation (DIC), and death. Treatment typically involves discontinuation of the offending agent(s), supportive care, and pharmacologic interventions such as cyproheptadine or cooling measures for hyperthermia.

'Receptors, Serotonin, 5-HT3' refer to a specific type of serotonin receptor called the 5-HT3 receptor, which is a ligand-gated ion channel found in the cell membrane. Serotonin, also known as 5-hydroxytryptamine (5-HT), is a neurotransmitter that plays a role in various physiological functions, including mood regulation, appetite control, and nausea.

The 5-HT3 receptor is activated by serotonin and mediates fast excitatory synaptic transmission in the central and peripheral nervous systems. It is permeable to sodium (Na+), potassium (K+), and calcium (Ca2+) ions, allowing for the rapid depolarization of neurons and the initiation of action potentials.

The 5-HT3 receptor has been a target for drug development, particularly in the treatment of chemotherapy-induced nausea and vomiting, as well as irritable bowel syndrome. Antagonists of the 5-HT3 receptor, such as ondansetron and granisetron, work by blocking the receptor and preventing serotonin from activating it, thereby reducing symptoms of nausea and vomiting.

Serotonin 5-HT1 receptor antagonists are a class of pharmaceutical drugs that block the activation of serotonin 5-HT1 receptors. Serotonin, also known as 5-hydroxytryptamine (5-HT), is a neurotransmitter that plays a role in various physiological functions, including mood regulation, appetite control, and sensory perception. The 5-HT1 receptor family includes several subtypes (5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, and 5-HT1F) that are widely distributed throughout the central and peripheral nervous systems.

When serotonin binds to these receptors, it triggers a series of intracellular signaling events that can have excitatory or inhibitory effects on neuronal activity. By blocking the interaction between serotonin and 5-HT1 receptors, antagonists modulate the downstream consequences of receptor activation.

Serotonin 5-HT1 receptor antagonists are used in various clinical contexts to treat or manage a range of conditions:

1. Migraine prevention: Some 5-HT1B/1D receptor antagonists, such as sumatriptan and rizatriptan, are highly effective in aborting migraine attacks by constricting dilated cranial blood vessels and reducing the release of pro-inflammatory neuropeptides.
2. Nausea and vomiting: Certain 5-HT3 receptor antagonists, like ondansetron and granisetron, are used to prevent chemotherapy-induced nausea and vomiting by blocking the activation of emetic circuits in the brainstem.
3. Psychiatric disorders: Although not widely used, some 5-HT1A receptor antagonists have shown promise in treating depression and anxiety disorders due to their ability to modulate serotonergic neurotransmission.
4. Neuroprotection: Preclinical studies suggest that 5-HT1A receptor agonists may have neuroprotective effects in various neurological conditions, such as Parkinson's disease and stroke. However, further research is needed to establish their clinical utility.

In summary, serotonin 5-HT1 receptor antagonists are a diverse group of medications with applications in migraine prevention, nausea and vomiting management, psychiatric disorders, and potential neuroprotection. Their unique pharmacological profiles enable them to target specific pathophysiological mechanisms underlying various conditions, making them valuable tools in modern therapeutics.

Serotonin 5-HT2 receptor agonists are a class of compounds that bind to and activate the serotonin 5-HT2 receptors, which are a type of G protein-coupled receptor found in the central and peripheral nervous systems. These receptors play important roles in various physiological processes, including neurotransmission, vasoconstriction, and smooth muscle contraction.

Serotonin 5-HT2 receptor agonists can produce a range of effects depending on the specific subtype of receptor they activate. For example, activation of 5-HT2A receptors has been associated with hallucinogenic effects, while activation of 5-HT2B receptors has been linked to cardiac valvulopathy.

These drugs are used in a variety of clinical settings, including the treatment of psychiatric disorders such as depression and schizophrenia, migraine headaches, and cluster headaches. Examples of serotonin 5-HT2 receptor agonists include LSD, psilocybin, ergotamine, and sumatriptan.

'Receptors, Serotonin, 5-HT4' refer to a specific type of serotonin receptor found in various parts of the body, including the central and peripheral nervous systems. These receptors are activated by the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT) and play an essential role in regulating several physiological functions, such as gastrointestinal motility, cognition, mood, and memory.

The 5-HT4 receptor is a G protein-coupled receptor (GPCR), which means it consists of seven transmembrane domains that span the cell membrane. When serotonin binds to the 5-HT4 receptor, it activates a signaling cascade within the cell, leading to various downstream effects.

The 5-HT4 receptor has been a target for drug development, particularly in treating gastrointestinal disorders such as constipation and irritable bowel syndrome (IBS). Additionally, some evidence suggests that 5-HT4 receptors may play a role in the treatment of depression, anxiety, and cognitive impairment. However, further research is needed to fully understand the therapeutic potential of targeting this receptor.

Serotonin 5-HT1 Receptor Agonists are a class of compounds that bind to and activate the serotonin 5-HT1 receptors, which are G protein-coupled receptors found in the central and peripheral nervous systems. These receptors play important roles in regulating various physiological functions, including neurotransmission, vasoconstriction, and hormone secretion.

Serotonin 5-HT1 Receptor Agonists are used in medical therapy to treat a variety of conditions, such as migraines, cluster headaches, depression, anxiety, and insomnia. Some examples of Serotonin 5-HT1 Receptor Agonists include sumatriptan, rizatriptan, zolmitriptan, naratriptan, and frovatriptan, which are used to treat migraines and cluster headaches by selectively activating the 5-HT1B/1D receptors in cranial blood vessels and sensory nerves.

Other Serotonin 5-HT1 Receptor Agonists, such as buspirone, are used to treat anxiety disorders and depression by acting on the 5-HT1A receptors in the brain. These drugs work by increasing serotonergic neurotransmission, which helps to regulate mood, cognition, and behavior.

Overall, Serotonin 5-HT1 Receptor Agonists are a valuable class of drugs that have shown efficacy in treating various neurological and psychiatric conditions. However, like all medications, they can have side effects and potential drug interactions, so it is important to use them under the guidance of a healthcare professional.

Tryptophan hydroxylase is an enzyme that plays a crucial role in the synthesis of neurotransmitters and hormones, including serotonin and melatonin. It catalyzes the conversion of the essential amino acid tryptophan to 5-hydroxytryptophan (5-HTP), which is then further converted to serotonin. This enzyme exists in two isoforms, TPH1 and TPH2, with TPH1 primarily located in peripheral tissues and TPH2 mainly found in the brain. The regulation of tryptophan hydroxylase activity has significant implications for mood, appetite, sleep, and pain perception.

Hormone antagonists are substances or drugs that block the action of hormones by binding to their receptors without activating them, thereby preventing the hormones from exerting their effects. They can be classified into two types: receptor antagonists and enzyme inhibitors. Receptor antagonists bind directly to hormone receptors and prevent the hormone from binding, while enzyme inhibitors block the production or breakdown of hormones by inhibiting specific enzymes involved in their metabolism. Hormone antagonists are used in the treatment of various medical conditions, such as cancer, hormonal disorders, and cardiovascular diseases.

Serotonin 5-HT3 receptor antagonists are a class of medications that work by blocking the serotonin 5-HT3 receptors, which are found in the gastrointestinal tract and the brain. These receptors play a role in regulating nausea and vomiting, among other functions.

When serotonin binds to these receptors, it can trigger a series of events that lead to nausea and vomiting, particularly in response to chemotherapy or surgery. By blocking the 5-HT3 receptors, serotonin cannot bind to them and therefore cannot trigger these events, which helps to reduce nausea and vomiting.

Examples of 5-HT3 receptor antagonists include ondansetron (Zofran), granisetron (Kytril), palonosetron (Aloxi), and dolasetron (Anzemet). These medications are commonly used to prevent and treat nausea and vomiting associated with chemotherapy, radiation therapy, and surgery.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Excitatory amino acid antagonists are a class of drugs that block the action of excitatory neurotransmitters, particularly glutamate and aspartate, in the brain. These drugs work by binding to and blocking the receptors for these neurotransmitters, thereby reducing their ability to stimulate neurons and produce an excitatory response.

Excitatory amino acid antagonists have been studied for their potential therapeutic benefits in a variety of neurological conditions, including stroke, epilepsy, traumatic brain injury, and neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, their use is limited by the fact that blocking excitatory neurotransmission can also have negative effects on cognitive function and memory.

There are several types of excitatory amino acid receptors, including N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and kainite receptors. Different excitatory amino acid antagonists may target one or more of these receptor subtypes, depending on their specific mechanism of action.

Examples of excitatory amino acid antagonists include ketamine, memantine, and dextromethorphan. These drugs have been used in clinical practice for various indications, such as anesthesia, sedation, and treatment of neurological disorders. However, their use must be carefully monitored due to potential side effects and risks associated with blocking excitatory neurotransmission.

Dopamine antagonists are a class of drugs that block the action of dopamine, a neurotransmitter in the brain associated with various functions including movement, motivation, and emotion. These drugs work by binding to dopamine receptors and preventing dopamine from attaching to them, which can help to reduce the symptoms of certain medical conditions such as schizophrenia, bipolar disorder, and gastroesophageal reflux disease (GERD).

There are several types of dopamine antagonists, including:

1. Typical antipsychotics: These drugs are primarily used to treat psychosis, including schizophrenia and delusional disorders. Examples include haloperidol, chlorpromazine, and fluphenazine.
2. Atypical antipsychotics: These drugs are also used to treat psychosis but have fewer side effects than typical antipsychotics. They may also be used to treat bipolar disorder and depression. Examples include risperidone, olanzapine, and quetiapine.
3. Antiemetics: These drugs are used to treat nausea and vomiting. Examples include metoclopramide and prochlorperazine.
4. Dopamine agonists: While not technically dopamine antagonists, these drugs work by stimulating dopamine receptors and can be used to treat conditions such as Parkinson's disease. However, they can also have the opposite effect and block dopamine receptors in high doses, making them functionally similar to dopamine antagonists.

Common side effects of dopamine antagonists include sedation, weight gain, and movement disorders such as tardive dyskinesia. It's important to use these drugs under the close supervision of a healthcare provider to monitor for side effects and adjust the dosage as needed.

Neurokinin-1 (NK-1) receptor antagonists are a class of drugs that block the action of substance P, a neuropeptide involved in pain transmission and inflammation. These drugs work by binding to NK-1 receptors found on nerve cells, preventing substance P from activating them and transmitting pain signals. NK-1 receptor antagonists have been studied for their potential use in treating various conditions associated with pain and inflammation, such as migraine headaches, depression, and irritable bowel syndrome. Some examples of NK-1 receptor antagonists include aprepitant, fosaprepitant, and rolapitant.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Narcotic antagonists are a class of medications that block the effects of opioids, a type of narcotic pain reliever, by binding to opioid receptors in the brain and blocking the activation of these receptors by opioids. This results in the prevention or reversal of opioid-induced effects such as respiratory depression, sedation, and euphoria. Narcotic antagonists are used for a variety of medical purposes, including the treatment of opioid overdose, the management of opioid dependence, and the prevention of opioid-induced side effects in certain clinical situations. Examples of narcotic antagonists include naloxone, naltrexone, and methylnaltrexone.

Histamine H2 antagonists, also known as H2 blockers, are a class of medications that work by blocking the action of histamine on the H2 receptors in the stomach. Histamine is a chemical that is released by the body during an allergic reaction and can also be released by certain cells in the stomach in response to food or other stimuli. When histamine binds to the H2 receptors in the stomach, it triggers the release of acid. By blocking the action of histamine on these receptors, H2 antagonists reduce the amount of acid produced by the stomach, which can help to relieve symptoms such as heartburn, indigestion, and stomach ulcers. Examples of H2 antagonists include ranitidine (Zantac), famotidine (Pepcid), and cimetidine (Tagamet).

Hydroxyindoleacetic acid (5HIAA) is a major metabolite of the neurotransmitter serotonin, formed in the body through the enzymatic degradation of serotonin by monoamine oxidase and aldehyde dehydrogenase. 5HIAA is primarily excreted in the urine and its measurement can be used as a biomarker for serotonin synthesis and metabolism in the body.

Increased levels of 5HIAA in the cerebrospinal fluid or urine may indicate conditions associated with excessive serotonin production, such as carcinoid syndrome, while decreased levels may be seen in certain neurodegenerative disorders, such as Parkinson's disease. Therefore, measuring 5HIAA levels can have diagnostic and therapeutic implications for these conditions.

Piperidines are not a medical term per se, but they are a class of organic compounds that have important applications in the pharmaceutical industry. Medically relevant piperidines include various drugs such as some antihistamines, antidepressants, and muscle relaxants.

A piperidine is a heterocyclic amine with a six-membered ring containing five carbon atoms and one nitrogen atom. The structure can be described as a cyclic secondary amine. Piperidines are found in some natural alkaloids, such as those derived from the pepper plant (Piper nigrum), which gives piperidines their name.

In a medical context, it is more common to encounter specific drugs that belong to the class of piperidines rather than the term itself.

Interleukin-1 Receptor Antagonist Protein (IL-1Ra) is a naturally occurring protein that acts as a competitive inhibitor of the interleukin-1 (IL-1) receptor. IL-1 is a pro-inflammatory cytokine involved in various physiological processes, including the immune response and inflammation. The binding of IL-1 to its receptor triggers a signaling cascade that leads to the activation of inflammatory genes and cellular responses.

IL-1Ra shares structural similarities with IL-1 but does not initiate the downstream signaling pathway. Instead, it binds to the same receptor site as IL-1, preventing IL-1 from interacting with its receptor and thus inhibiting the inflammatory response.

Increased levels of IL-1Ra have been found in various inflammatory conditions, such as rheumatoid arthritis, inflammatory bowel disease, and sepsis, where it acts to counterbalance the pro-inflammatory effects of IL-1. Recombinant IL-1Ra (Anakinra) is used clinically as a therapeutic agent for the treatment of rheumatoid arthritis and other inflammatory diseases.

Muscarinic antagonists, also known as muscarinic receptor antagonists or parasympatholytics, are a class of drugs that block the action of acetylcholine at muscarinic receptors. Acetylcholine is a neurotransmitter that plays an important role in the parasympathetic nervous system, which helps to regulate various bodily functions such as heart rate, digestion, and respiration.

Muscarinic antagonists work by binding to muscarinic receptors, which are found in various organs throughout the body, including the eyes, lungs, heart, and gastrointestinal tract. By blocking the action of acetylcholine at these receptors, muscarinic antagonists can produce a range of effects depending on the specific receptor subtype that is affected.

For example, muscarinic antagonists may be used to treat conditions such as chronic obstructive pulmonary disease (COPD) and asthma by relaxing the smooth muscle in the airways and reducing bronchoconstriction. They may also be used to treat conditions such as urinary incontinence or overactive bladder by reducing bladder contractions.

Some common muscarinic antagonists include atropine, scopolamine, ipratropium, and tiotropium. It's important to note that these drugs can have significant side effects, including dry mouth, blurred vision, constipation, and confusion, especially when used in high doses or for prolonged periods of time.

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) medication that is primarily used to treat major depressive disorder, obsessive-compulsive disorder, bulimia nervosa, panic disorder, and premenstrual dysphoric disorder. It works by increasing the levels of serotonin, a neurotransmitter in the brain that helps maintain mental balance.

Fluoxetine is available under the brand name Prozac and is also available as a generic medication. It comes in various forms, including capsules, tablets, delayed-release capsules, and liquid solution. The typical starting dose for adults with depression is 20 mg per day, but the dosage may be adjusted based on individual patient needs and response to treatment.

Fluoxetine has a relatively long half-life, which means it stays in the body for an extended period of time. This can be beneficial for patients who may have difficulty remembering to take their medication daily, as they may only need to take it once or twice a week. However, it also means that it may take several weeks for the full effects of the medication to become apparent.

As with any medication, fluoxetine can cause side effects, including nausea, dry mouth, sleepiness, insomnia, dizziness, and headache. In some cases, it may also increase the risk of suicidal thoughts or behavior in children, adolescents, and young adults, particularly during the initial stages of treatment. It is important for patients to discuss any concerns about side effects with their healthcare provider.

GABA (gamma-aminobutyric acid) antagonists are substances that block the action of GABA, which is the primary inhibitory neurotransmitter in the central nervous system. GABA plays a crucial role in regulating neuronal excitability and reducing the transmission of nerve impulses.

GABA antagonists work by binding to the GABA receptors without activating them, thereby preventing the normal function of GABA and increasing neuronal activity. These agents can cause excitation of the nervous system, leading to various effects depending on the specific type of GABA receptor they target.

GABA antagonists are used in medical treatments for certain conditions, such as sleep disorders, depression, and cognitive enhancement. However, they can also have adverse effects, including anxiety, agitation, seizures, and even neurotoxicity at high doses. Examples of GABA antagonists include picrotoxin, bicuculline, and flumazenil.

The Raphe Nuclei are clusters of neurons located in the brainstem, specifically in the midline of the pons, medulla oblongata, and mesencephalon (midbrain). These neurons are characterized by their ability to synthesize and release serotonin, a neurotransmitter that plays a crucial role in regulating various functions such as mood, appetite, sleep, and pain perception.

The Raphe Nuclei project axons widely throughout the central nervous system, allowing serotonin to modulate the activity of other neurons. There are several subdivisions within the Raphe Nuclei, each with distinct connections and functions. Dysfunction in the Raphe Nuclei has been implicated in several neurological and psychiatric disorders, including depression, anxiety, and chronic pain.

Histamine H1 antagonists, also known as H1 blockers or antihistamines, are a class of medications that work by blocking the action of histamine at the H1 receptor. Histamine is a chemical mediator released by mast cells and basophils in response to an allergic reaction or injury. It causes various symptoms such as itching, sneezing, runny nose, and wheal and flare reactions (hives).

H1 antagonists prevent the binding of histamine to its receptor, thereby alleviating these symptoms. They are commonly used to treat allergic conditions such as hay fever, hives, and eczema, as well as motion sickness and insomnia. Examples of H1 antagonists include diphenhydramine (Benadryl), loratadine (Claritin), cetirizine (Zyrtec), and doxylamine (Unisom).

5-Hydroxytryptophan (5-HTP) is a chemical compound that is produced by the body as a precursor to serotonin, a neurotransmitter that helps regulate mood, appetite, sleep, and pain sensation. 5-HTP is not present in food but can be derived from the amino acid tryptophan, which is found in high-protein foods such as turkey, chicken, milk, and cheese.

5-HTP supplements are sometimes used to treat conditions related to low serotonin levels, including depression, anxiety, insomnia, migraines, and fibromyalgia. However, the effectiveness of 5-HTP for these conditions is not well established, and it can have side effects and interact with certain medications. Therefore, it's important to consult a healthcare provider before taking 5-HTP supplements.

Citalopram is a type of antidepressant known as a selective serotonin reuptake inhibitor (SSRI). It works by increasing the levels of serotonin, a neurotransmitter in the brain that helps maintain mental balance. Citalopram is primarily used to treat major depressive disorder and is also sometimes used to treat anxiety disorders, such as panic disorder or social anxiety disorder.

The medical definition of Citalopram can be described as follows:

Citalopram (brand name Celexa) is a selective serotonin reuptake inhibitor (SSRI) antidepressant that is primarily used to treat major depressive disorder. It works by increasing the levels of serotonin, a neurotransmitter in the brain that helps maintain mental balance. Citalopram may also be used off-label for the treatment of anxiety disorders, such as panic disorder or social anxiety disorder.

Common side effects of citalopram include nausea, dry mouth, increased sweating, sleepiness, fatigue, and insomnia. More serious side effects can include an increased risk of suicidal thoughts or behavior in children, adolescents, and young adults, as well as an increased risk of bleeding, particularly if taken with other medications that increase the risk of bleeding. Citalopram should be used with caution in patients with a history of heart disease, liver disease, or seizure disorders. It is important to follow the dosage instructions provided by your healthcare provider and to inform them of any other medications you are taking, as well as any medical conditions you have, before starting citalopram.

Purinergic P1 receptor antagonists are a class of pharmaceutical drugs that block the activity of purinergic P1 receptors, which are a type of G-protein coupled receptor found in many tissues throughout the body. These receptors are activated by extracellular nucleotides such as adenosine and ATP, and play important roles in regulating a variety of physiological processes, including cardiovascular function, neurotransmission, and immune response.

Purinergic P1 receptor antagonists work by binding to these receptors and preventing them from being activated by nucleotides. This can have various therapeutic effects, depending on the specific receptor subtype that is targeted. For example, A1 receptor antagonists have been shown to improve cardiac function in heart failure, while A2A receptor antagonists have potential as anti-inflammatory and neuroprotective agents.

However, it's important to note that the use of purinergic P1 receptor antagonists is still an area of active research, and more studies are needed to fully understand their mechanisms of action and therapeutic potential.

Serotonergic neurons are specialized types of nerve cells (neurons) that produce, synthesize, and release the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT). These neurons have their cell bodies located in specific brainstem nuclei, such as the dorsal raphe nucleus and median raphe nucleus. They project and innervate various regions of the central nervous system, including the cerebral cortex, hippocampus, hypothalamus, and other brain areas. Serotonergic neurons play crucial roles in regulating numerous physiological functions, such as mood, appetite, sleep, memory, cognition, and sensorimotor activities. Alterations in serotonergic neurotransmission have been implicated in several neurological and psychiatric disorders, including depression, anxiety, schizophrenia, and neurodevelopmental conditions.

Histamine antagonists, also known as histamine blockers or H1-blockers, are a class of medications that work by blocking the action of histamine, a substance in the body that is released during an allergic reaction. Histamine causes many of the symptoms of an allergic response, such as itching, sneezing, runny nose, and hives. By blocking the effects of histamine, these medications can help to relieve or prevent allergy symptoms.

Histamine antagonists are often used to treat conditions such as hay fever, hives, and other allergic reactions. They may also be used to treat stomach ulcers caused by excessive production of stomach acid. Some examples of histamine antagonists include diphenhydramine (Benadryl), loratadine (Claritin), and famotidine (Pepcid).

It's important to note that while histamine antagonists can be effective at relieving allergy symptoms, they do not cure allergies or prevent the release of histamine. They simply block its effects. It's also worth noting that these medications can have side effects, such as drowsiness, dry mouth, and dizziness, so it's important to follow your healthcare provider's instructions carefully when taking them.

Nicotinic antagonists are a class of drugs that block the action of nicotine at nicotinic acetylcholine receptors (nAChRs). These receptors are found in the nervous system and are activated by the neurotransmitter acetylcholine, as well as by nicotine. When nicotine binds to these receptors, it can cause the release of various neurotransmitters, including dopamine, which can lead to rewarding effects and addiction.

Nicotinic antagonists work by binding to nAChRs and preventing nicotine from activating them. This can help to reduce the rewarding effects of nicotine and may be useful in treating nicotine addiction. Examples of nicotinic antagonists include mecamylamine, varenicline, and cytisine.

It's important to note that while nicotinic antagonists can help with nicotine addiction, they can also have side effects, such as nausea, vomiting, and abnormal dreams. Additionally, some people may experience more serious side effects, such as seizures or cardiovascular problems, so it's important to use these medications under the close supervision of a healthcare provider.

Adrenergic alpha-1 receptor antagonists, also known as alpha-blockers, are a class of medications that block the effects of the neurotransmitter norepinephrine at alpha-1 receptors. These receptors are found in various tissues throughout the body, including the smooth muscle of blood vessels, the bladder, and the eye.

When norepinephrine binds to alpha-1 receptors, it causes smooth muscle to contract, leading to vasoconstriction (constriction of blood vessels), increased blood pressure, and other effects. By blocking these receptors, alpha-blockers can cause relaxation of smooth muscle, leading to vasodilation (expansion of blood vessels), decreased blood pressure, and other effects.

Alpha-blockers are used in the treatment of various medical conditions, including hypertension (high blood pressure), benign prostatic hyperplasia (enlarged prostate), and pheochromocytoma (a rare tumor of the adrenal gland). Examples of alpha-blockers include doxazosin, prazosin, and terazosin.

It's important to note that while alpha-blockers can be effective in treating certain medical conditions, they can also have side effects, such as dizziness, lightheadedness, and orthostatic hypotension (a sudden drop in blood pressure when standing up). As with any medication, it's important to use alpha-blockers under the guidance of a healthcare provider.

"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.

Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.

Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.

Adenosine A2 receptor antagonists are a class of pharmaceutical compounds that block the action of adenosine at A2 receptors. Adenosine is a naturally occurring molecule in the body that acts as a neurotransmitter and has various physiological effects, including vasodilation and inhibition of heart rate.

Adenosine A2 receptor antagonists work by binding to A2 receptors and preventing adenosine from activating them. This results in the opposite effect of adenosine, leading to vasoconstriction and increased heart rate. These drugs are used for a variety of medical conditions, including asthma, chronic obstructive pulmonary disease (COPD), and heart failure.

Examples of Adenosine A2 receptor antagonists include theophylline, caffeine, and some newer drugs such asistradefylline and tozadenant. These drugs have different pharmacological properties and are used for specific medical conditions. It is important to note that adenosine A2 receptor antagonists can have side effects, including restlessness, insomnia, and gastrointestinal symptoms, and should be used under the guidance of a healthcare professional.

Purinergic P2 receptor antagonists are pharmaceutical agents that block the activity of P2 receptors, which are a type of cell surface receptor that binds extracellular nucleotides such as ATP and ADP. These receptors play important roles in various physiological processes, including neurotransmission, inflammation, and platelet aggregation.

P2 receptors are divided into two main subfamilies: P2X and P2Y. The P2X receptors are ligand-gated ion channels that allow the flow of ions across the cell membrane upon activation, while the P2Y receptors are G protein-coupled receptors that activate intracellular signaling pathways.

Purinergic P2 receptor antagonists are used in clinical medicine to treat various conditions, such as chronic pain, urinary incontinence, and cardiovascular diseases. For example, the P2X3 receptor antagonist gefapixant is being investigated for the treatment of refractory chronic cough, while the P2Y12 receptor antagonists clopidogrel and ticagrelor are used to prevent thrombosis in patients with acute coronary syndrome.

Overall, purinergic P2 receptor antagonists offer a promising therapeutic approach for various diseases by targeting specific receptors involved in pathological processes.

Paroxetine is a selective serotonin reuptake inhibitor (SSRI) medication that is primarily used to treat major depressive disorders, obsessive-compulsive disorder, panic disorder, social anxiety disorder, generalized anxiety disorder, and post-traumatic stress disorder. It works by increasing the levels of serotonin, a neurotransmitter in the brain that helps maintain mental balance, leading to an improvement in mood and other symptoms associated with these conditions.

Paroxetine is available under various brand names, such as Paxil and Seroxat, and it comes in different forms, including tablets, capsules, and liquid solutions. The medication is typically taken once daily, although the dosage may vary depending on the individual's needs and the specific condition being treated.

As with any medication, paroxetine can have side effects, such as nausea, dizziness, dry mouth, and sleep disturbances. In some cases, it may also cause more serious side effects, including increased risk of suicidal thoughts or behaviors in children, adolescents, and young adults, as well as an increased risk of bleeding and hyponatremia (low sodium levels).

It is important to consult with a healthcare provider before starting paroxetine or any other medication, and to follow their instructions carefully regarding dosage, timing, and potential interactions with other drugs or medical conditions.

Fenclonine is not a commonly used medical term or a medication in clinical practice. It's possible that you may have encountered this term in the context of research or scientific studies. Fenclonine is an experimental drug that has been investigated for its potential role as an inhibitor of bacterial enzymes, specifically the D-alanine:D-alanine ligase (DD-transpeptidase) involved in bacterial cell wall biosynthesis.

Inhibiting this enzyme can disrupt the integrity and growth of bacteria, making fenclonine a potential antibiotic agent. However, further research is required to establish its safety, efficacy, and therapeutic applications. As such, it's not currently used as a standard treatment option in human medicine.

For accurate information regarding medical definitions or treatments, consult with healthcare professionals or refer to reputable medical resources.

Piperazines are a class of heterocyclic organic compounds that contain a seven-membered ring with two nitrogen atoms at positions 1 and 4. They have the molecular formula N-NRR' where R and R' can be alkyl or aryl groups. Piperazines have a wide range of uses in pharmaceuticals, agrochemicals, and as building blocks in organic synthesis.

In a medical context, piperazines are used in the manufacture of various drugs, including some antipsychotics, antidepressants, antihistamines, and anti-worm medications. For example, the antipsychotic drug trifluoperazine and the antidepressant drug nefazodone both contain a piperazine ring in their chemical structure.

However, it's important to note that some piperazines are also used as recreational drugs due to their stimulant and euphoric effects. These include compounds such as BZP (benzylpiperazine) and TFMPP (trifluoromethylphenylpiperazine), which have been linked to serious health risks, including addiction, seizures, and death. Therefore, the use of these substances should be avoided.

A serotonin receptor, specifically the 5-HT1D subtype, is a type of G protein-coupled receptor found in the central and peripheral nervous systems. These receptors are activated by the neurotransmitter serotonin (5-hydroxytryptamine or 5-HT) and play important roles in regulating various physiological functions, including neurotransmission, vasoconstriction, and nociception (pain perception).

The 5-HT1D receptor subtype is further divided into several subtypes, including 5-HT1Dα, 5-HT1Dβ, and 5-HT1Dε. These receptors are widely distributed throughout the brain and spinal cord, where they modulate neurotransmission by inhibiting adenylyl cyclase activity and reducing cAMP levels in neurons.

In addition to their role in regulating neurotransmission, 5-HT1D receptors have also been implicated in a variety of neurological and psychiatric disorders, including migraine, depression, anxiety, and addiction. As a result, drugs that target these receptors have been developed for the treatment of these conditions. For example, triptans, which are commonly used to treat migraines, work by selectively activating 5-HT1D receptors in the brain and constricting blood vessels in the meninges, thereby reducing the inflammation and pain associated with migraines.

Dopamine is a type of neurotransmitter, which is a chemical messenger that transmits signals in the brain and nervous system. It plays several important roles in the body, including:

* Regulation of movement and coordination
* Modulation of mood and motivation
* Control of the reward and pleasure centers of the brain
* Regulation of muscle tone
* Involvement in memory and attention

Dopamine is produced in several areas of the brain, including the substantia nigra and the ventral tegmental area. It is released by neurons (nerve cells) and binds to specific receptors on other neurons, where it can either excite or inhibit their activity.

Abnormalities in dopamine signaling have been implicated in several neurological and psychiatric conditions, including Parkinson's disease, schizophrenia, and addiction.

'Animal behavior' refers to the actions or responses of animals to various stimuli, including their interactions with the environment and other individuals. It is the study of the actions of animals, whether they are instinctual, learned, or a combination of both. Animal behavior includes communication, mating, foraging, predator avoidance, and social organization, among other things. The scientific study of animal behavior is called ethology. This field seeks to understand the evolutionary basis for behaviors as well as their physiological and psychological mechanisms.

A radioligand assay is a type of in vitro binding assay used in molecular biology and pharmacology to measure the affinity and quantity of a ligand (such as a drug or hormone) to its specific receptor. In this technique, a small amount of a radioactively labeled ligand, also known as a radioligand, is introduced to a sample containing the receptor of interest. The radioligand binds competitively with other unlabeled ligands present in the sample for the same binding site on the receptor. After allowing sufficient time for binding, the reaction is stopped, and the amount of bound radioligand is measured using a technique such as scintillation counting. The data obtained from this assay can be used to determine the dissociation constant (Kd) and maximum binding capacity (Bmax) of the receptor-ligand interaction, which are important parameters in understanding the pharmacological properties of drugs and other ligands.

Adrenergic alpha-2 receptor antagonists are a class of medications that block the action of norepinephrine, a neurotransmitter and hormone, at adrenergic alpha-2 receptors. These receptors are found in the central and peripheral nervous system and play a role in regulating various physiological functions such as blood pressure, heart rate, and insulin secretion.

By blocking the action of norepinephrine at these receptors, adrenergic alpha-2 receptor antagonists can increase sympathetic nervous system activity, leading to vasodilation, increased heart rate, and increased insulin secretion. These effects make them useful in the treatment of conditions such as hypotension (low blood pressure), opioid-induced sedation and respiratory depression, and diagnostic procedures that require vasodilation.

Examples of adrenergic alpha-2 receptor antagonists include yohimbine, idazoxan, and atipamezole. It's important to note that these medications can have significant side effects, including hypertension, tachycardia, and agitation, and should be used under the close supervision of a healthcare provider.

5,7-Dihydroxytryptamine is a chemical compound that is a derivative of the neurotransmitter serotonin. It is formed by the hydroxylation of serotonin at the 5 and 7 positions of its indole ring. This compound is not typically found in significant concentrations in the body, but it can be synthesized and used for research purposes.

In the laboratory, 5,7-Dihydroxytryptamine has been used as a tool to study the role of serotonin in various physiological processes. For example, researchers have used this compound to selectively destroy serotonergic neurons in animal models, allowing them to investigate the functions of these neurons and their contributions to behavior and brain function.

It is important to note that 5,7-Dihydroxytryptamine is not a medication or therapeutic agent, and it should only be used in research settings under the guidance of trained professionals.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

I'm sorry for any confusion, but "Pyridines" is not a medical term. It is a chemical term that refers to a class of organic compounds with the chemical structure of a six-membered ring containing one nitrogen atom and five carbon atoms (heterocyclic aromatic compound).

In a biological or medical context, pyridine derivatives can be found in various natural and synthetic substances. For example, some medications contain pyridine rings as part of their chemical structure. However, "Pyridines" itself is not a medical term or condition.

Adenosine A1 receptor antagonists are a class of pharmaceutical compounds that block the action of adenosine at A1 receptors. Adenosine is a naturally occurring purine nucleoside that acts as a neurotransmitter and modulator of various physiological processes, including cardiovascular function, neuronal excitability, and immune response.

Adenosine exerts its effects by binding to specific receptors on the surface of cells, including A1, A2A, A2B, and A3 receptors. The activation of A1 receptors leads to a variety of physiological responses, such as vasodilation, negative chronotropy (slowing of heart rate), and negative inotropy (reduced contractility) of the heart, as well as inhibition of neurotransmitter release in the brain.

Adenosine A1 receptor antagonists work by binding to and blocking the action of adenosine at A1 receptors, thereby preventing or reducing its effects on these physiological processes. These drugs have been investigated for their potential therapeutic uses in various conditions, such as heart failure, cardiac arrest, and neurological disorders.

Examples of adenosine A1 receptor antagonists include:

* Dipyridamole: a vasodilator used to treat peripheral arterial disease and to prevent blood clots.
* Caffeine: a natural stimulant found in coffee, tea, and chocolate, which acts as a weak A1 receptor antagonist.
* Rolofylline: an experimental drug that has been investigated for its potential use in treating acute ischemic stroke and traumatic brain injury.
* KW-3902: another experimental drug that has been studied for its potential therapeutic effects in heart failure, cardiac arrest, and neurodegenerative disorders.

It's important to note that adenosine A1 receptor antagonists may have side effects and potential risks, and their use should be monitored and managed by healthcare professionals.

Leukotriene antagonists are a class of medications that work by blocking the action of leukotrienes, which are chemicals released by the immune system in response to an allergen or irritant. Leukotrienes cause airway muscles to tighten and inflammation in the airways, leading to symptoms such as wheezing, shortness of breath, and coughing. By blocking the action of leukotrienes, leukotriene antagonists can help relieve these symptoms and improve lung function. These medications are often used to treat asthma and allergic rhinitis (hay fever). Examples of leukotriene antagonists include montelukast, zafirlukast, and pranlukast.

Adrenergic alpha-antagonists, also known as alpha-blockers, are a class of medications that block the effects of adrenaline and noradrenaline at alpha-adrenergic receptors. These receptors are found in various tissues throughout the body, including the smooth muscle of blood vessels, the heart, the genitourinary system, and the eyes.

When alpha-blockers bind to these receptors, they prevent the activation of the sympathetic nervous system, which is responsible for the "fight or flight" response. This results in a relaxation of the smooth muscle, leading to vasodilation (widening of blood vessels), decreased blood pressure, and increased blood flow.

Alpha-blockers are used to treat various medical conditions, such as hypertension (high blood pressure), benign prostatic hyperplasia (enlarged prostate), pheochromocytoma (a rare tumor of the adrenal gland), and certain types of glaucoma.

Examples of alpha-blockers include doxazosin, prazosin, terazosin, and tamsulosin. Side effects of alpha-blockers may include dizziness, lightheadedness, headache, weakness, and orthostatic hypotension (a sudden drop in blood pressure upon standing).

Angiotensin receptor antagonists (ARAs), also known as angiotensin II receptor blockers (ARBs), are a class of medications used to treat hypertension, heart failure, and protect against kidney damage in patients with diabetes. They work by blocking the action of angiotensin II, a potent vasoconstrictor and hormone that increases blood pressure and promotes tissue fibrosis. By blocking the binding of angiotensin II to its receptors, ARAs cause relaxation of blood vessels, decreased sodium and water retention, and reduced cardiac remodeling, ultimately leading to improved cardiovascular function and reduced risk of organ damage. Examples of ARAs include losartan, valsartan, irbesartan, and candesartan.

Adrenergic antagonists, also known as beta blockers or sympatholytic drugs, are a class of medications that block the effects of adrenaline and noradrenaline (also known as epinephrine and norepinephrine) on the body. These neurotransmitters are part of the sympathetic nervous system and play a role in the "fight or flight" response, increasing heart rate, blood pressure, and respiratory rate.

Adrenergic antagonists work by binding to beta-adrenergic receptors in the body, preventing the neurotransmitters from activating them. This results in a decrease in heart rate, blood pressure, and respiratory rate. These medications are used to treat various conditions such as hypertension, angina, heart failure, arrhythmias, glaucoma, and anxiety disorders.

There are two types of adrenergic antagonists: beta blockers and alpha blockers. Beta blockers selectively bind to beta-adrenergic receptors, while alpha blockers bind to alpha-adrenergic receptors. Some medications, such as labetalol, have both beta and alpha blocking properties.

It is important to note that adrenergic antagonists can interact with other medications and may cause side effects, so it is essential to use them under the guidance of a healthcare professional.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

A drug interaction is the effect of combining two or more drugs, or a drug and another substance (such as food or alcohol), which can alter the effectiveness or side effects of one or both of the substances. These interactions can be categorized as follows:

1. Pharmacodynamic interactions: These occur when two or more drugs act on the same target organ or receptor, leading to an additive, synergistic, or antagonistic effect. For example, taking a sedative and an antihistamine together can result in increased drowsiness due to their combined depressant effects on the central nervous system.
2. Pharmacokinetic interactions: These occur when one drug affects the absorption, distribution, metabolism, or excretion of another drug. For example, taking certain antibiotics with grapefruit juice can increase the concentration of the antibiotic in the bloodstream, leading to potential toxicity.
3. Food-drug interactions: Some drugs may interact with specific foods, affecting their absorption, metabolism, or excretion. An example is the interaction between warfarin (a blood thinner) and green leafy vegetables, which can increase the risk of bleeding due to enhanced vitamin K absorption from the vegetables.
4. Drug-herb interactions: Some herbal supplements may interact with medications, leading to altered drug levels or increased side effects. For instance, St. John's Wort can decrease the effectiveness of certain antidepressants and oral contraceptives by inducing their metabolism.
5. Drug-alcohol interactions: Alcohol can interact with various medications, causing additive sedative effects, impaired judgment, or increased risk of liver damage. For example, combining alcohol with benzodiazepines or opioids can lead to dangerous levels of sedation and respiratory depression.

It is essential for healthcare providers and patients to be aware of potential drug interactions to minimize adverse effects and optimize treatment outcomes.

Biogenic monoamines are a type of neurotransmitter, which are chemical messengers that transmit signals in the brain and other parts of the nervous system. They are called "biogenic" because they are derived from biological substances, and "monoamines" because they contain one amine group (-NH2) and are derived from the aromatic amino acids: tryptophan, tyrosine, and phenylalanine.

Examples of biogenic monoamines include:

1. Serotonin (5-hydroxytryptamine or 5-HT): synthesized from the amino acid tryptophan and plays a crucial role in regulating mood, appetite, sleep, memory, and learning.
2. Dopamine: formed from tyrosine and is involved in reward, motivation, motor control, and reinforcement of behavior.
3. Norepinephrine (noradrenaline): also derived from tyrosine and functions as a neurotransmitter and hormone that modulates attention, arousal, and stress responses.
4. Epinephrine (adrenaline): synthesized from norepinephrine and serves as a crucial hormone and neurotransmitter in the body's fight-or-flight response to stress or danger.
5. Histamine: produced from the amino acid histidine, it acts as a neurotransmitter and mediates allergic reactions, immune responses, and regulates wakefulness and appetite.

Imbalances in biogenic monoamines have been linked to various neurological and psychiatric disorders, such as depression, anxiety, Parkinson's disease, and schizophrenia. Therefore, medications that target these neurotransmitters, like selective serotonin reuptake inhibitors (SSRIs) for depression or levodopa for Parkinson's disease, are often used in the treatment of these conditions.

GABA-A receptor antagonists are pharmacological agents that block the action of gamma-aminobutyric acid (GABA) at GABA-A receptors. GABA is the primary inhibitory neurotransmitter in the central nervous system, and it exerts its effects by binding to GABA-A receptors, which are ligand-gated chloride channels. When GABA binds to these receptors, it opens the chloride channel, leading to an influx of chloride ions into the neuron and hyperpolarization of the membrane, making it less likely to fire.

GABA-A receptor antagonists work by binding to the GABA-A receptor and preventing GABA from binding, thereby blocking the inhibitory effects of GABA. This can lead to increased neuronal excitability and can result in a variety of effects depending on the specific antagonist and the location of the receptors involved.

GABA-A receptor antagonists have been used in research to study the role of GABA in various physiological processes, and some have been investigated as potential therapeutic agents for conditions such as anxiety, depression, and insomnia. However, their use is limited by their potential to cause seizures and other adverse effects due to excessive neuronal excitation. Examples of GABA-A receptor antagonists include picrotoxin, bicuculline, and flumazenil.

"Competitive binding" is a term used in pharmacology and biochemistry to describe the behavior of two or more molecules (ligands) competing for the same binding site on a target protein or receptor. In this context, "binding" refers to the physical interaction between a ligand and its target.

When a ligand binds to a receptor, it can alter the receptor's function, either activating or inhibiting it. If multiple ligands compete for the same binding site, they will compete to bind to the receptor. The ability of each ligand to bind to the receptor is influenced by its affinity for the receptor, which is a measure of how strongly and specifically the ligand binds to the receptor.

In competitive binding, if one ligand is present in high concentrations, it can prevent other ligands with lower affinity from binding to the receptor. This is because the higher-affinity ligand will have a greater probability of occupying the binding site and blocking access to the other ligands. The competition between ligands can be described mathematically using equations such as the Langmuir isotherm, which describes the relationship between the concentration of ligand and the fraction of receptors that are occupied by the ligand.

Competitive binding is an important concept in drug development, as it can be used to predict how different drugs will interact with their targets and how they may affect each other's activity. By understanding the competitive binding properties of a drug, researchers can optimize its dosage and delivery to maximize its therapeutic effect while minimizing unwanted side effects.

Norepinephrine, also known as noradrenaline, is a neurotransmitter and a hormone that is primarily produced in the adrenal glands and is released into the bloodstream in response to stress or physical activity. It plays a crucial role in the "fight-or-flight" response by preparing the body for action through increasing heart rate, blood pressure, respiratory rate, and glucose availability.

As a neurotransmitter, norepinephrine is involved in regulating various functions of the nervous system, including attention, perception, motivation, and arousal. It also plays a role in modulating pain perception and responding to stressful or emotional situations.

In medical settings, norepinephrine is used as a vasopressor medication to treat hypotension (low blood pressure) that can occur during septic shock, anesthesia, or other critical illnesses. It works by constricting blood vessels and increasing heart rate, which helps to improve blood pressure and perfusion of vital organs.

Antidepressive agents are a class of medications used to treat various forms of depression and anxiety disorders. They act on neurotransmitters, the chemical messengers in the brain, to restore the balance that has been disrupted by mental illness. The most commonly prescribed types of antidepressants include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs). These medications can help alleviate symptoms such as low mood, loss of interest in activities, changes in appetite and sleep patterns, fatigue, difficulty concentrating, and thoughts of death or suicide. It is important to note that antidepressants may take several weeks to reach their full effectiveness and may cause side effects, so it is essential to work closely with a healthcare provider to find the right medication and dosage.

Serotonin 5-HT4 receptor antagonists are a class of pharmaceutical drugs that block the action of serotonin at 5-HT4 receptors. Serotonin, also known as 5-hydroxytryptamine (5-HT), is a neurotransmitter involved in various physiological functions, including mood regulation, gastrointestinal motility, and cognition.

The 5-HT4 receptor is one of several subtypes of serotonin receptors found throughout the body, particularly in the brain, gastrointestinal tract, and cardiovascular system. These receptors are involved in regulating various physiological processes, including gastrointestinal motility, cognition, and mood regulation.

Serotonin 5-HT4 receptor antagonists work by binding to these receptors and preventing serotonin from activating them. This action can have various therapeutic effects, depending on the specific drug and its intended use. For example, some 5-HT4 receptor antagonists are used to treat gastrointestinal disorders such as irritable bowel syndrome (IBS) and gastroparesis, as they help slow down gastrointestinal motility and reduce symptoms such as diarrhea and abdominal pain.

Examples of 5-HT4 receptor antagonists include drugs such as alosetron, cisapride (now withdrawn from the market due to safety concerns), and prucalopride. These drugs are typically administered orally and have varying degrees of selectivity for the 5-HT4 receptor subtype.

It's important to note that while 5-HT4 receptor antagonists can have therapeutic effects, they can also have side effects, including constipation, nausea, and headache. Additionally, some of these drugs may interact with other medications or have potentially serious adverse effects, so it's essential to use them under the guidance of a healthcare professional.

Indole is not strictly a medical term, but it is a chemical compound that can be found in the human body and has relevance to medical and biological research. Indoles are organic compounds that contain a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered pyrrole ring.

In the context of medicine, indoles are particularly relevant due to their presence in certain hormones and other biologically active molecules. For example, the neurotransmitter serotonin contains an indole ring, as does the hormone melatonin. Indoles can also be found in various plant-based foods, such as cruciferous vegetables (e.g., broccoli, kale), and have been studied for their potential health benefits.

Some indoles, like indole-3-carbinol and diindolylmethane, are found in these vegetables and can have anti-cancer properties by modulating estrogen metabolism, reducing inflammation, and promoting cell death (apoptosis) in cancer cells. However, it is essential to note that further research is needed to fully understand the potential health benefits and risks associated with indoles.

Ritanserin is a medication that belongs to the class of drugs known as serotonin antagonists. It works by blocking the action of serotonin, a neurotransmitter in the brain, which helps to reduce anxiety and improve mood. Ritanserin was initially developed for the treatment of depression and schizophrenia, but its development was discontinued due to its side effects.

The medical definition of Ritanserin is:

A piperazine derivative and a serotonin antagonist that has been used in the treatment of depression and schizophrenia. Its therapeutic effect is thought to be related to its ability to block the action of serotonin at 5HT2 receptors. However, development of ritanserin was discontinued due to its side effects, including orthostatic hypotension, dizziness, and sedation. It has also been studied for its potential in treating cocaine addiction and alcohol withdrawal syndrome.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Tryptamines are a class of organic compounds that contain a tryptamine skeleton, which is a combination of an indole ring and a ethylamine side chain. They are commonly found in nature and can be synthesized in the lab. Some tryptamines have psychedelic properties and are used as recreational drugs, such as dimethyltryptamine (DMT) and psilocybin. Others have important roles in the human body, such as serotonin, which is a neurotransmitter that regulates mood, appetite, and sleep. Tryptamines can also be found in some plants and animals, including certain species of mushrooms, toads, and catnip.

Histamine H3 antagonists, also known as inverse agonists, are a class of drugs that block the activity of histamine at the H3 receptor. Histamine is a naturally occurring neurotransmitter and autacoid involved in various physiological functions, including the modulation of wakefulness and arousal, regulation of food intake, and control of blood pressure and fluid balance.

The H3 receptor is primarily located in the central nervous system (CNS) and acts as an auto-receptor on histamine-containing neurons to regulate the release of histamine. By blocking the activity of these receptors, histamine H3 antagonists increase the release of histamine in the CNS, which can lead to increased wakefulness and arousal.

Histamine H3 antagonists have been studied for their potential therapeutic use in various neurological and psychiatric disorders, including narcolepsy, attention deficit hyperactivity disorder (ADHD), and Alzheimer's disease. However, further research is needed to fully understand the clinical benefits and safety of these drugs.

A serotonin antagonist, or serotonin receptor antagonist, is a drug used to inhibit the action of serotonin and serotonergic ... Wikimedia Commons has media related to Serotonin receptor antagonists. Serotonin+Antagonists at the U.S. National Library of ... the antidepressant mirtazapine acts as a 5-HT3 antagonist. Although some non-selective serotonin antagonists may have a ... "Oral serotonin type 3-receptor antagonists for prevention of chemotherapy-induced emesis". American Journal of Health-System ...
... s (SARIs) are a class of drugs used mainly as antidepressants, but also as ... They act by antagonizing serotonin receptors such as 5-HT2A and inhibiting the reuptake of serotonin, norepinephrine, and/or ... a related drug but does not fit into this class as it does not function as a serotonin antagonist, acting solely as a 5-HT1A ... as it is a serotonin-dopamine reuptake inhibitor and 5-HT2A and 5-HT2C receptor antagonist, but not grouped as such. Lubazodone ...
Anthony M (1984). "Serotonin antagonists". Aust N Z J Med. 14 (6): 888-895. doi:10.1111/j.1445-5994.1984.tb03802.x. PMID ... Serotonin also forms several salts, including pharmaceutical formulation of serotonin adipate. Serotonin is involved in ... also produces serotonin, coumaroyl-serotonin, and feruloyl-serotonin in response to F. graminearum. This produces a slight ... If serotonin is released in the blood faster than the platelets can absorb it, the level of free serotonin in the blood is ...
... a serotonin antagonist". Journal of Allergy. 31: 237-47. doi:10.1016/0021-8707(60)90052-6. PMID 14409112. (All articles with ...
Veasey, Sigrid C. (1 February 2003). "Serotonin Agonists and Antagonists in Obstructive Sleep Apnea". American Journal of ...
Ebdrup BH, Rasmussen H, Arnt J, Glenthøj B (September 2011). "Serotonin 2A receptor antagonists for treatment of schizophrenia ... 5-HT2A antagonists, Antipsychotics, Isoindoles, Ketones, Organofluorides, Piperidines, Sigma antagonists, All stub articles, ... Roluperidone (former developmental code names MIN-101, CYR-101, MT-210) is a 5-HT2A and σ2 receptor antagonist under ... "5-Hydroxytryptamine 2A receptor antagonists as potential treatment for psychiatric disorders". Expert Opinion on ...
If this is not sufficient, a serotonin antagonist such as cyproheptadine may be used. In those with a high body temperature, ... The serotonin antagonist cyproheptadine is the recommended initial therapy, although there have been no controlled trials ... Nisijima K, Yoshino T, Yui K, Katoh S (January 2001). "Potent serotonin (5-HT)(2A) receptor antagonists completely prevent the ... Management is based primarily on stopping the usage of the precipitating drugs, the administration of serotonin antagonists ...
... is a 5-HT3 antagonist, commonly known as a setron. These drugs act by blocking serotonin from binding to the 5-HT3 ... ISBN 978-3-7741-9846-3. Billio A, Morello E, Clarke MJ (January 2010). Billio A (ed.). "Serotonin receptor antagonists for ... It has a longer duration of action than other 5-HT3 antagonists. The oral formulation was approved on August 22, 2008, for ... There are case reports about serotonin syndrome when the drug is combined with serotonergic substances such as selective ...
Serotonin antagonists and dantrolene may be used as required. Despite the seriousness of the condition, the majority of ... Serotonin releasing agents, Serotonin receptor agonists, Methoxy compounds). ... However, relative to MDMA, it is considerably less effective as a releaser of serotonin with properties more akin to a reuptake ... PMA acts as a selective serotonin releasing agent (SSRA) with weak effects on dopamine and norepinephrine transporters. ...
Zivin JA, Venditto JA (April 1984). "Experimental CNS ischemia: serotonin antagonists reduce or prevent damage". Neurology. 34 ... Mehta MA, Tricklebank MD (2019). "Serotonin and the psychedelics". The Serotonin System. pp. 193-202. doi:10.1016/B978-0-12- ... It was found to bind to many of the same receptors as LSD, but acting as a neutral antagonist rather than an agonist. 2-Bromo- ... Harvey JA (2003). "Role of the serotonin 5-HT(2A) receptor in learning". Learning & Memory. 10 (5): 355-362. doi:10.1101/lm. ...
Trazodone is a potent 5-HT2A antagonist, as well as an antagonist on other serotonin receptors. Brexpiprazole an atypical ... Another antagonist is cyproheptadine. Pizotifen is a non-selective antagonist. LY-367,265 - dual 5-HT2A antagonist / SSRI with ... Yadav PN, Kroeze WK, Farrell MS, Roth BL (October 2011). "Antagonist functional selectivity: 5-HT2A serotonin receptor ... Sanders-Bush E, Mayer SE (2006). "Chapter 11: 5-Hydroxytryptamine (Serotonin): Receptor Agonists and Antagonists". In Brunton ...
These include benzodiazepines, β-adrenergic blockers, and serotonin antagonists. Another major cause of the syndrome is the ... and serotonin antagonists such as cyproheptadine may also be of help in treating acute akathisia but are much less effective ... Role of Serotonin 5-HT2a Receptor Antagonists". Drugs (Review). 80 (9): 871-882. doi:10.1007/s40265-020-01312-0. PMID 32385739 ... Dunkley, E.J.C.; Isbister, G.K.; Sibbritt, D.; Dawson, A.H.; Whyte, I.M. (18 August 2003). "The Hunter Serotonin Toxicity ...
Dopamine antagonists, Local anesthetics, Muscarinic antagonists, Piperidines, 5-HT2 antagonists, Serotonin receptor antagonists ... Of the serotonin receptors, it is an especially potent antagonist of the 5-HT2 receptors. This is thought to underlie its ... a potent in vivo serotonin antagonist". The American Journal of Psychiatry. 154 (6): 884a-884. doi:10.1176/ajp.154.6.884a. PMID ... such as selective serotonin reuptake inhibitors (and monoamine oxidase inhibitors), and in cases of high levels of serotonin in ...
Serotonin receptor antagonist "Eltoprazine - Elto Pharma - AdisInsight". Capi M, de Andrés F, Lionetto L, Gentile G, Cipolla F ... A serotonin receptor agonist is an agonist of one or more serotonin receptors. They activate serotonin receptors in a manner ... Activation of the 5-HT2A receptor is also implicated in serotonin syndrome caused by indirect serotonin receptor agonists like ... serotonin reuptake inhibitors, serotonin releasing agents, and monoamine oxidase inhibitors. Antagonists of the 5-HT2A receptor ...
It is a serotonin antagonist both in vitro and in vivo (it is a 5-HT2D receptor antagonist). It also neutralises other ... "Effect of serotonin antagonists on patients with atypical facial pain". Journal of Craniomandibular Disorders. 3 (4): 211-2. ...
Benhamú B, Martín-Fontecha M, Vázquez-Villa H, Pardo L, López-Rodríguez ML (2014). "Serotonin 5-HT6 receptor antagonists for ... Geldenhuys WJ, Van der Schyf CJ (2008). "Serotonin 5HT6 receptor antagonists for the treatment of Alzheimer's disease". Current ... 5HT7 antagonist Idalopirdine (Lu AE58054) - selective Intepirdine (SB-742,457/RVT-101) - selective antagonist Landipirdine (RO- ... 5HT6 antagonists have also been shown to reduce appetite and produce weight loss, and as a result, PRX-07034, BVT-5,182, and ...
It is a serotonin antagonist and histamine antagonist. The Sandmeyer reaction on o-(4-Dimethylaminosulfonyl-2-nitrophenylthio) ... H1 receptor antagonists, Phenothiazines, Serotonin receptor antagonists, Sulfonamides, All stub articles, Analgesic stubs). ...
It is a serotonin 5-HT3 receptor antagonist. It does not have any effect on dopamine receptors or muscarinic receptors. ... Ondansetron is a highly selective serotonin 5-HT3 receptor antagonist, with low affinity for dopamine receptors. The 5-HT3 ... Serotonin is released by the enterochromaffin cells of the small intestine in response to chemotherapeutic agents and may ... "Pharmacokinetic profile of the selective 5-HT3 receptor antagonist ondansetron in the rat: an original study and a minireview ...
... (INN) is a serotonin 5-HT3 receptor antagonist. Prakash SP, Cable KM, Correa ID, Fellows L, Montgomery S, Newman JJ ... 5-HT3 antagonists, Imidazoles, Gamma-Carbolines, All stub articles, Gastrointestinal system drug stubs). ... Waterhouse L, Wells GN, Sutherland DR (1995). "Synthesis of isotopically labelled pyridoindolone 5-HT3 receptor antagonists". ...
5-HT3 receptor antagonists or serotonin antagonists were first introduced in the early 1990s, and they have become the most ... Sirota P, Mosheva T, Shabtay H, Giladi N, Korczyn AD (2000). "Use of the selective serotonin 3 receptor antagonist ondansetron ... The 5-HT3 receptor antagonists suppress vomiting and nausea by inhibiting serotonin binding to the 5-HT3 receptors. The highest ... 5-HT3 receptor antagonists are more likely to bind in their protonated form. Docking of a range of antagonists into a homology ...
... is a drug which was the first compound developed to act as a selective antagonist for the serotonin receptor 5-HT5A, ... August 2020). "Antagonists of the serotonin receptor 5A target human breast tumor initiating cells". BMC Cancer. 20 (1): 724. ... "Serotonin type 5A receptor antagonists inhibit D-lysergic acid diethylamide discriminatory cue in rats". Journal of ... Nikiforuk A, Hołuj M, Kos T, Popik P (June 2016). "The effects of a 5-HT5A receptor antagonist in a ketamine-based rat model of ...
"Ketanserin and spiperone as templates for novel serotonin 5-HT(2A) antagonists". Current Topics in Medicinal Chemistry. 2 (6): ... It functions as a highly selective 5-HT2A receptor antagonist, with negligible affinity for the 5-HT1A or 5-HT2C receptors, and ... 5-HT2A antagonists, Fluoroarenes, Aromatic ketones, Spiro compounds, Imidazolidinones, All stub articles, Nervous system drug ...
Serotonin antagonist and reuptake inhibitor Alan F. Schatzberg, M.D.; Charles B. Nemeroff, M.D., Ph.D. (2017). The American ... 5-HT2A antagonists, Alpha-1 blockers, Antidepressants, Chloroarenes, H1 receptor antagonists, Human drug metabolites, Meta- ... Triazoledione shows significant affinity for the serotonin 5-HT1A and 5-HT2A receptors, the α1-adrenergic receptor, and the ... It shows negligible affinity for the serotonin and norepinephrine transporters and the muscarinic acetylcholine receptors. ...
Serotonin antagonist and reuptake inhibitor Alan F. Schatzberg, M.D.; Charles B. Nemeroff, M.D., Ph.D. (2017). The American ... H1 receptor antagonists, Human drug metabolites, Meta-Chlorophenylpiperazines, Secondary alcohols, Serotonin-norepinephrine ...
Terry AV, Buccafusco JJ, Bartoszyk GD (June 2005). "Selective serotonin 5-HT2A receptor antagonist EMD 281014 improves delayed ... a selective serotonin 2A receptor antagonist on anxiety induced by predator stress in rats". European Journal of Pharmacology. ... a new selective serotonin 5-HT2A receptor antagonist". European Journal of Pharmacology. 473 (2-3): 229-30. doi:10.1016/S0014- ... "Effects of the serotonin 5-HT2A/2C receptor agonist DOI and of the selective 5-HT2A or 5-HT2C receptor antagonists EMD 281014 ...
Treatment by serotonin and dopamine antagonists caused a reduction in the behavioral abnormalities. Ataxia, trembling, ... The serotonin and dopamine systems are thought to be involved in the behavioral abnormalities caused by allyl cyanide. ...
Second-line treatments include vitamin B6 +/- doxylamine, antihistamines, dopamine antagonists, and serotonin antagonists. ...
Hence, anticholinergics, antihistamines, dopamine antagonists, serotonin antagonists, and cannabinoids are used as antiemetics ... Opioids Selective serotonin reuptake inhibitors Many chemotherapy drugs Some entheogens (such as peyote or ayahuasca) High ... serotonin 5-HT3 receptors, opioid receptors, acetylcholine receptors, and receptors for substance P. Stimulation of different ...
5-HT3 antagonists, Anilines, Benzamides, Chloroarenes, Phenol ethers, Quinuclidines, Respiratory agents, Serotonin receptor ... a single-blind serotonin type 3 antagonist trial". Archives of General Psychiatry. 49 (9): 751-2. doi:10.1001/archpsyc. ... Zacopride is a potent antagonist at the 5-HT3 receptor and an agonist at the 5-HT4 receptor. It has anxiolytic and nootropic ... Smith WW, Sancilio LF, Owera-Atepo JB, Naylor RJ, Lambert L (April 1988). "Zacopride, a potent 5-HT3 antagonist". The Journal ...
Miyake, N; Miyamoto, S; Jarskog, LF (October 2012). "New serotonin/dopamine antagonists for the treatment of schizophrenia: are ... The atypical antipsychotics (AAP), also known as second generation antipsychotics (SGAs) and serotonin-dopamine antagonists ( ... 5-HT6 receptor antagonists improve cognition, learning, and memory. The 5-HT7 receptor is very potent for the mitigation of ... H1 antagonism blocks serotonin and norepinephrine reuptake. Patients with increased histamine levels have been observed to have ...
A serotonin antagonist, or serotonin receptor antagonist, is a drug used to inhibit the action of serotonin and serotonergic ... Wikimedia Commons has media related to Serotonin receptor antagonists. Serotonin+Antagonists at the U.S. National Library of ... the antidepressant mirtazapine acts as a 5-HT3 antagonist. Although some non-selective serotonin antagonists may have a ... "Oral serotonin type 3-receptor antagonists for prevention of chemotherapy-induced emesis". American Journal of Health-System ...
Alpha-1 Receptor Antagonists. Class Summary. Novel pilot studies in combat veterans suggest alpha-1 antagonists have efficacy ... Selective serotonin reuptake inhibitors. Class Summary. The selective serotonin reuptake inhibitors (SSRIs) work by blocking ... It is a potent, selective inhibitor of neuronal serotonin reuptake. It also has a weak effect on norepinephrine and dopamine ... Fluoxetine selectively inhibits presynaptic serotonin reuptake with minimal or no effect on the reuptake of norepinephrine or ...
Atypical antipsychotics (serotonin dopamine receptor antagonists). Class Summary. Atypical (or second generation) ... Tetrabenazine is a presynaptic dopamine antagonist with minimal risk of tardive dystonia. It is designated as an orphan drug in ... Clozapine binds to dopamine D2 receptor with 20 times lower affinity than for serotonin-2 receptor. ...
Aleksandrov PN The Study of the Influence of Histamine and Serotonin Antagonists on Inflammation Byull. Éksp.Biol.Med 1975 79(3 ... The effects of an antihistamine (diphenhydramine hydroch - loride) and serotonin antagonists (morphine D-LSD-25,tipindole) on ... "The Study of the Influence of Histamine and Serotonin Antagonists on Inflammation". ... "The Study of the Influence of Histamine and Serotonin Antagonists on Inflammation" Byull. Éksp.Biol.Med. 1975;79(3):26-29. ...
Serotonin antagonists. Serotonin antagonists are often used to counter nausea and vomiting resulting from chemotherapy drugs ... Serotonin antagonists stop serotonin (a substance occurring naturally in the brain) from sending a signal that causes vomiting ... Other similar serotonin antagonists include ondansetron (Zofran and others), granisetron (Kytril) and dolasetron (Anzemet). ... Aprepitant is sometimes given in combination with corticosteroids and serotonin antagonists. It is available as a capsule and ...
Serotonin Receptor Antagonists: Safety in Surgery Patients. Home KS Projects Serotonin Receptor Antagonists: Safety in Surgery ... Serotonin Receptor Antagonists: Efficacy in Surgery Patients (Prev Entry) (Next Entry) Serotonin Receptor Antagonists and ... Serotonin receptor antagonists: efficacy in surgery patients. *Serotonin receptor antagonists and chemotherapy administered to ... Comparative safety of serotonin (5-HT3) receptor antagonists in patients undergoing surgery: a systematic review and network ...
Serotonin Antagonists are intended to treat Depression. Learn more about Serotonin Antagonists. ... How much do serotonin antagonists cost?. Serotonin antagonists are very expensive with an average cost of up to $5,000 per year ... What conditions are serotonin antagonists used to treat?. Serotonin antagonists are used in several conditions, including:. * ... Are serotonin antagonists safe?. The use of serotonin antagonists is relatively safe and effective when taken as prescribed. ...
That gene codes for the 5-HT3 receptor, a protein that responds to the brain-signaling chemical serotonin.. To confirm these ...
Atypical antipsychotics (serotonin dopamine receptor antagonists). Class Summary. Atypical antipsychotics (eg, clozapine, ... Tetrabenazine is a presynaptic dopamine antagonist with minimal risk of tardive dystonia. It is designated as an orphan drug in ... Clozapine binds to dopamine D2 receptor with 20 times lower affinity than for serotonin-2 receptor. ...
Serotonin Antagonists / therapeutic use * Serotonin and Noradrenaline Reuptake Inhibitors / therapeutic use * Tapentadol ... We restored DNIC in spinal nerve ligated animals by blocking 5-HT3 descending facilitations with the antagonist ondansetron or ... α2 adrenoceptor mechanisms underlie DNIC because the antagonists, yohimbine and atipamezole, markedly attenuated this ... a serotonin, NRI) in patients. We suggest that pharmacological strategies through manipulation of the monoamine system could be ...
Serotonin Antagonists * Serotonin * Heparin * Iproniazid ...
Attenuating effect of serotonin receptor antagonists on impairment of mealtime-associated activity rhythm in old rats. In: ... Attenuating effect of serotonin receptor antagonists on impairment of mealtime-associated activity rhythm in old rats. / ... Attenuating effect of serotonin receptor antagonists on impairment of mealtime-associated activity rhythm in old rats. ... In the present study, we examined attenuating effect of serotonin (5-HT) receptor antagonists on the impairment of the time ...
Ondansetron belongs to a group of drugs called serotonin 5-HT3 antagonists, which block serotonin, a natural chemical in the ... Ondansetron prevents nausea and vomiting by blocking the bodys production of serotonin. Ondansetron can cause headaches, ... reactions have been reported in patients who are allergic to other selective 5-HT3 receptor antagonists. ...
Serotonin antagonist. Methysergide. D. Contraindicated. Table 3. Risks of Drug Therapies for Restless Leg Syndrome in Pregnancy ...
Now, scientists have discovered that selectively blocking a serotonin receptor subtype induces fast-acting antidepressant ... Serotonin 2C receptor antagonists induce fast-onset antidepressant effects. Molecular Psychiatry, October 2013 ... Serotonin Transporters Increase When Depression Fades. May 10, 2021 Low levels of serotonin in the brain are seen as a possible ... They looked at different subtypes of serotonin receptors, proteins that are binding partners for serotonin, a neurotransmitter ...
Dose-ranging evaluation of the serotonin antagonist dolasetron mesylate in patients receiving high-dose cisplatin. Journal of ... Dose-ranging evaluation of the serotonin antagonist dolasetron mesylate in patients receiving high-dose cisplatin. In: Journal ... Dose-ranging evaluation of the serotonin antagonist dolasetron mesylate in patients receiving high-dose cisplatin. / Kris, Mark ... Dive into the research topics of Dose-ranging evaluation of the serotonin antagonist dolasetron mesylate in patients receiving ...
The serotonin antagonist cyproheptadine is the recommended initial therapy, although there have been no controlled trials ... Serotonin syndrome. Other names. Serotonin toxicity, serotonin toxidrome, serotonin sickness, serotonin storm, serotonin ... Nisijima K, Yoshino T, Yui K, Katoh S (January 2001). "Potent serotonin (5-HT)(2A) receptor antagonists completely prevent the ... Management is based primarily on stopping the usage of the precipitating drugs, the administration of serotonin antagonists ...
Serotonin antagonist drugs, which act on serotonin receptors. Other treatments may include:. *Botulinum toxin (Botox) injected ...
Domperidone belongs to the group of medications called dopamine antagonists. It is used to treat slowed movement in the ... selective serotonin reuptake inhibitors (SSRIS; e.g., citalopram, fluoxetine, paroxetine, sertraline). *serotonin antagonists ( ... Domperidone belongs to the group of medications called dopamine antagonists. It is used to treat slowed movement in the ...
selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline). *serotonin antagonists ( ...
Desvenlafaxine belongs to the class of antidepressant medications known as selective serotonin and norepinephrine reuptake ... other serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., desvenlafaxine, duloxetine). *serotonin antagonists (anti- ... Serotonin syndrome or neuroleptic malignant syndrome: This medication may cause the rare but potentially life-threatening ... selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline, vortioxetine) ...
Serotonin (5-HT3) receptor antagonists for the reduction of symptoms of low anterior resection syndrome Itagaki R, Koda K, ...
Methysergide (UML-491), a new serotonin antagonist Scientific Exhibit, .... 1960. Volmat R, Rosolato G, Wia.... Recherches exp ... The action of serotonin and lysergic acid diethylamide on spinal refle... J. Pharmacol. & Expe.... 1955. ... Serotonin Binding to Nerve-Ending Particles of the Rat Brain and Its I... Science. 1964. ... Serotonin binding to nerve-ending particles of the rat brain and its i... Science. 1964. ...
Structure activity relationships of 5-HT and 5-HT serotonin receptor antagonists: N, C2 and 5′-Modified (N)-methanocarba- ... N)-Methanocarba adenosine derivatives were structurally modified to target 5-HT serotonin receptors as antagonists, ...
The effects of serotonin antagonists in an animal model of sleep-disordered breathing. Am J Respir Crit Care Med. 1996;153(2): ... Intranodose ganglion injections of dronabinol attenuate serotonin-induced apnea in Sprague-Dawley rat. Respir Physiol Neurobiol ... Intracerebroventricular injections of dronabinol, a cannabinoid receptor agonist, does not attenuate serotonin-induced apnea in ... such as nabilone and dronabinol may have short-term benefit for sleep apnea due to their modulatory effects on serotonin- ...
Serotonin antagonists Serotonin (5-HT3) antagonists, such as ondansetron and granisetron, are highly effective antiemetics, but ... However, in cases of severe nausea and vomiting, using serotonin antagonists is reasonable. Examples of potential dosages for ...
... are dopamine antagonists that block serotonin receptors and affect serotonin levels. Serotonin is a hormone that contributes to ...
... if it not to much trouble could some1 help me pronouce the word serotonin? thnx ... Medical Health side effects caused by serotonin-dopamine-antagonist-antipsychotics *. Dec 12, 2022. ... Suggested for: Pronounce Serotonin: Fun Post Help No clear link between low serotonin and depression - study ... sort of a funny post, if it not to much trouble could some1 help me pronouce the word serotonin? thnx ...
Serotonin S2 receptor antagonist (Naftidrofuryl) - Arteriolar vasodilation, improved blood flow in Raynaud syndrome ... N -methyl-D-aspartate (NMDA) receptor antagonist (Memantine) - Prevents binding of glutamate and resultant calcium influx; ...
Serotonin (5HT3) antagonists. A04A. ANTIEMETICS AND ANTINAUSEANTS. A04. ANTIEMETICS AND ANTINAUSEANTS. A. Alimentary tract and ...
  • A serotonin antagonist, or serotonin receptor antagonist, is a drug used to inhibit the action of serotonin and serotonergic drugs at serotonin (5-HT) receptors. (wikipedia.org)
  • Risperidone antipsychotic Trazodone Nefazodone Another subclass consists of drugs selectively acting at the 5-HT3 receptors, and thus are known as 5-HT3 antagonists. (wikipedia.org)
  • These medications can affect other serotonin receptors in your body which may lead to an increased incidence of side effects and drug interactions. (nicerx.com)
  • After being released, the serotonin binds to receptors in your stomach and transmits impulses through the central nervous system (CNS) to an area of your brain known as the vomiting center. (nicerx.com)
  • 5-HT3 receptor blockers reduce nausea and vomiting through the binding and inhibition of the serotonin receptors involved in this process. (nicerx.com)
  • SARIs act by binding to 5-HT2A receptors and blocking the reuptake of neurotransmitters such as serotonin, histamine, norepinephrine, and dopamine. (nicerx.com)
  • They looked at different subtypes of serotonin receptors, proteins that are binding partners for serotonin, a neurotransmitter that has been shown to regulate mood, memory and appetite. (sciencedaily.com)
  • Of these subtypes, serotonin 2C receptors stood out. (sciencedaily.com)
  • We observed fast-acting therapeutic effects in multiple behavioral tasks after we administered compounds that selectively block serotonin 2C receptors," said Mark Opal, a graduate student at the University of Chicago and lead author of the paper. (sciencedaily.com)
  • Serotonin 2C receptors normally inhibit the release of dopamine, another neurotransmitter commonly associated with mood, from certain neurons. (sciencedaily.com)
  • Some current antidepressants on the market already affect serotonin 2C receptors, although not selectively, and Dulawa believes the safety profile is favorable for human use. (sciencedaily.com)
  • The second generation, or atypical antipsychotics, are dopamine antagonists that block serotonin receptors and affect serotonin levels. (medicalnewstoday.com)
  • Drugs with serotoninergic properties have the ability to increase the level of serotonin or to act as direct agonists of postsynaptic serotonin receptors in the central nervous system (CNS). (medscape.com)
  • SCH 23390 and SK&F 83566 are antagonists at vascular DA and serotonin receptors. (rndsystems.com)
  • Rault, S Novel antagonists of serotonin-4 receptors: synthesis and biological evaluation of pyrrolothienopyrazines. (bindingdb.org)
  • It acts as a partial agonist at serotonin 5-HT1A and dopamine D2 receptors, and as an antagonist at serotonin 5-HT2A and noradrenaline α1B/α2C receptors. (lundbeck.com)
  • Ziprasidone functioned as a selective antagonist at the D 2 , 5HT 2A , and 5HT 1D receptors, and also as an agonist at the 5HT 1A receptor. (tcichemicals.com)
  • They include, but are not limited to: Chlorpromazine Cyproheptadine Metergoline Methysergide Mianserin Mirtazapine Oxetorone Pizotifen Propranolol Ritanserin Spiperone Carbinoxamine Cinnarizine Cyproheptadine Hydroxyzine Methdilazine Pizotifen Promethazine Pizotifen is a 5-HT2C antagonist, H1 blocker and anticholinergic useful in migraine prophylaxis. (wikipedia.org)
  • [1] If this is not sufficient, a serotonin antagonist such as cyproheptadine may be used. (wikipedia.org)
  • Cyproheptadine is a histamine and serotonin antagonist used to treat allergic reactions. (healthnews.com)
  • Cyproheptadine is a serotonin and histamine antagonist with anticholinergic and sedative effects. (nih.gov)
  • Cyproheptadine, both a histamine as well as serotonin antagonist, can act as an antidote. (healthyplace.com)
  • Antiserotonin and antihistamine drugs appear to compete with serotonin and histamine, respectively, for receptor sites. (nih.gov)
  • They include, but are not limited to: Dolasetron Granisetron Ondansetron Palonosetron Tropisetron Other 5-HT3 antagonists have been considered for use in the treatment of irritable bowel syndrome: Alosetron Cilansetron Also, the antidepressant mirtazapine acts as a 5-HT3 antagonist. (wikipedia.org)
  • The first 5-HT3, or serotonin receptor antagonist to be approved for use by the FDA was ondansetron. (nicerx.com)
  • First-generation 5-HT3 receptor antagonists examples include Zofran (ondansetron) and Sancuso (granisetron). (nicerx.com)
  • Can serotonin 5-HT3 receptor antagonist ondansetron (Zofran) prevent opioid withdrawral symptoms? (opioids.wiki)
  • We restored DNIC in spinal nerve ligated animals by blocking 5-HT3 descending facilitations with the antagonist ondansetron or by enhancing norepinephrine modulation through the use of reboxetine (a norepinephrine reuptake inhibitor, NRI) or tapentadol (μ-opioid receptor agonist and NRI). (nih.gov)
  • Ondansetron prevents nausea and vomiting by blocking the body's production of serotonin. (rxwiki.com)
  • Ondansetron belongs to a group of drugs called serotonin 5-HT3 antagonists, which block serotonin, a natural chemical in the body, from causing nausea and vomiting. (rxwiki.com)
  • The newer antiemetics used for the prevention and treatment of PONV are 5HT 3 receptor antagonists (ondansetron, granisetron, tropisetron, dolasetron) are devoid of these side effects. (ispub.com)
  • The use of these 5-HT 3 receptor antagonists have been shown to improve patients' satisfaction, decrease recovery and discharge times and reduced an unanticipated hospital admission especially when they are used prophylactically 25 26 .This prospective, randomized, double blind placebo controlled study was undertaken to compare the efficacy of granisetron and ondansetron in prevention PONV in patients undergoing gynecological laparoscopic surgeries. (ispub.com)
  • Tetrabenazine is a presynaptic dopamine antagonist with minimal risk of tardive dystonia. (medscape.com)
  • the dopamine hypersensitivity hypothesis and the serotonin-dopamine antagonist hypothesis. (who.int)
  • The neuroleptic-induced TD with those who did serotonin-dopamine antagonist hypothesis not develop it under comparatively similar maintains that drugs which have a high conditions. (who.int)
  • The selective serotonin reuptake inhibitors (SSRIs) work by blocking the reuptake of serotonin. (medscape.com)
  • When used for these conditions, they are classified as serotonin antagonist and reuptake inhibitors (SARIs) and include Desyrel (trazodone). (nicerx.com)
  • Serotonin antagonist and reuptake inhibitors (SARIs) are typically used as antidepressants. (nicerx.com)
  • Desvenlafaxine belongs to the class of antidepressant medications known as selective serotonin and norepinephrine reuptake inhibitors (SNRIs). (medbroadcast.com)
  • Diphenhydramine, an anticholinergic with H1 antagonist properties, also has antidystonic effects. (medscape.com)
  • Compounds that specifically inhibit the reuptake of serotonin in the brain. (bvsalud.org)
  • Tremor is a common side effect of MDMA 's action on dopamine , whereas hyperreflexia is symptomatic of exposure to serotonin agonists . (wikipedia.org)
  • The action of serotonin and lysergic acid diethylamide on spinal refle. (erowid.org)
  • Reserpine Depletes serotonin stores in the brain, heart, and many other organs and has been used in hypertension and psychosis Gamma-mangostin from Garcinia mangostana Serotonin receptor agonist Lindley, C. (wikipedia.org)
  • Sumatriptan is a selective serotonin receptor agonist. (singhealth.com.sg)
  • Fluoxetine selectively inhibits presynaptic serotonin reuptake with minimal or no effect on the reuptake of norepinephrine or dopamine. (medscape.com)
  • Nefazodone is an antidepressant with both presynaptic serotonin and norepinephrine reuptake properties as well as postsynaptic 5-HT 2A blockade characteristics. (antidepressantsfacts.com)
  • The majority of concerning combinations involve the use of a monoamine oxidase inhibitor (MAOI), a selective serotonin reuptake inhibitor (SSRI), or a serotonin-norepinephrine reuptake inhibitor (SNRI). (medscape.com)
  • While akathisia is most commonly expressed following the use of antipsychotic medication, often it may be observed resulting from the use of antidepressant therapy, in particular drugs of the selective serotonin reuptake inhibitor (SSRI) class expressing serotonin-2A (5-HT 2A ) stimulatory effects. (antidepressantsfacts.com)
  • Where your pets have an unbalanced level of serotonin, it can lead to irrational behavior such as lashing out and separation anxiety. (petplace.com)
  • [6] (Many of these symptoms may be side effects of the drug or drug interaction causing excessive levels of serotonin rather than an effect of elevated serotonin itself. (wikipedia.org)
  • What this means is that Trazodone regulates and increases the levels of serotonin in the brain. (petplace.com)
  • Now, scientists have discovered that selectively blocking a serotonin receptor subtype induces fast-acting antidepressant effects in mice, indicating a potential new class of therapeutics for depression. (sciencedaily.com)
  • Now, scientists from the University of Chicago have discovered that selectively blocking a serotonin receptor subtype induces fast-acting antidepressant effects in mice, indicating a potential new class of therapeutics for depression. (sciencedaily.com)
  • Antagonists of the 5-HT2A receptor are sometimes used as atypical antipsychotics (contrast with typical antipsychotics, which are purely dopamine antagonists). (wikipedia.org)
  • Ziprasidone hydrochloride monohydrate is a benzisothiazolyl piperazine-type atypical antipsychotic that shares the serotonin 2A /dopamine 2 (5-HT 2A /D 2 ) profile of the atypical antipsychotics. (tcichemicals.com)
  • In the perioperative setting, it may prove challenging to differentiate serotonin toxicity from other syndromes that have similar manifestations. (medscape.com)
  • Complete a free online enrollment application to find out if you're eligible to pay only $49 per month for your Serotonin Antagonists medication with our help. (nicerx.com)
  • Serotonin syndrome ( SS ) is a group of symptoms that may occur with the use of certain serotonergic medications or drugs . (wikipedia.org)
  • Serotonin syndrome is typically caused by the use of two or more serotonergic medications or drugs. (wikipedia.org)
  • Domperidone belongs to the group of medications called dopamine antagonists . (medbroadcast.com)
  • Although some non-selective serotonin antagonists may have a particular affinity for a specific 5-HT receptor (and thus may be listed below e.g., methysergide), they still may also possess a generalised non-selective action. (wikipedia.org)
  • Clozapine binds to dopamine D2 receptor with 20 times lower affinity than for serotonin-2 receptor. (medscape.com)
  • The effects of an antihistamine (diphenhydramine hydroch - loride) and serotonin antagonists (morphine D-LSD-25,tipindole) on the development of the inflammatory process was studied. (erowid.org)
  • It is a potent, selective inhibitor of neuronal serotonin reuptake. (medscape.com)
  • Brexpiprazole is a small molecule and a potent serotonin-dopamine activity modulator. (lundbeck.com)
  • The serotonin, dopamine, and noradrenaline neurotransmitter systems may be implicated in behavioral symptoms of dementia, including agitation. (lundbeck.com)
  • [6] Onset of symptoms is typically within a day of the extra serotonin. (wikipedia.org)
  • Compared with serotonin syndrome, which presents within 24 hours of exposure, NMS usually has a more gradual onset, generally presenting in days to weeks. (medscape.com)
  • PCPA) An inhibitor of serotonin synthesis that has been used in the treatment of carcinoid syndrome. (wikipedia.org)
  • Serotonin syndrome is classically described as involving a combination of autonomic hyperactivity, hemodynamic changes, neuromuscular derangements, and changes in mental status. (medscape.com)
  • Serotonin syndrome can be precipitated by pharmaceuticals, botanicals, and recreational drugs. (medscape.com)
  • The utility of these criteria notwithstanding, diagnosis of serotonin syndrome can be challenging, particularly in the perioperative setting. (medscape.com)
  • Serotonin syndrome can have a variety of clinical presentations, but the majority of cases manifest within 24 hours of a change of dose or initiation of a drug. (medscape.com)
  • Serotonin syndrome can manifest with findings that range from benign to fatal. (medscape.com)
  • NMS is the condition most commonly cited in the differential diagnosis when serotonin syndrome is a concern. (medscape.com)
  • Several naturally occurring protein transmitters, including ones called serotonin and substance P, are released, triggering the nausea and vomiting reflex. (cancercare.org)
  • These new selective 5-HT3 receptor antagonists marked a significant improvement in the treatment of nausea and vomiting. (nicerx.com)
  • 5-HT3 receptor antagonists are a class of prescription drugs best known as antiemetics used for the treatment or prevention of nausea and vomiting due to chemotherapy, radiation therapy, or surgery. (nicerx.com)
  • α2 adrenoceptor mechanisms underlie DNIC because the antagonists, yohimbine and atipamezole, markedly attenuated this descending inhibition. (nih.gov)
  • Hypersensitivit y (allergic) reactions have been reported in patients who are allergic to other selective 5-HT 3 receptor antagonists. (rxwiki.com)
  • 12. Yonehara N. Influence of serotonin receptor antagonists on substance P and serotonin release evoked by tooth stimulation with electroacupuncture in the trigeminal nucleus caudalis of the rabbit. (bvsalud.org)
  • In the present study, we examined attenuating effect of serotonin (5-HT) receptor antagonists on the impairment of the time perception presented by daily scheduled feeding in old rats. (elsevierpure.com)
  • Daily injections of 5-HT 2 receptor antagonists, mianserin or ritanserin, or a 5-HT 3 receptor antagonist, Y25130, at 1700 h for 6 consecutive days significantly and dose-dependently attenuated the impairment of mealtime-associated activity on the fasting day in old rats without affecting the food intake. (elsevierpure.com)
  • Effects of DA D 1 antagonists SCH23390 and SK&F83566 on locomotor activities in rats. (rndsystems.com)
  • Trazodone is categorized as a SARI which stands for Serotonin Antagonist Reuptake Inhibitor. (petplace.com)
  • On the other hand, morphine D- LSD-25 and tipindole in concentrations corresponding to their D-antisero - tonin activity had an evident anti-inflammatory effect probably due to indomethacin-like activity as well as d-serotonin blockade since they are indole derivatives. (erowid.org)
  • Certain serotonin antagonists are used in the treatment of depression , insomnia, and mood disorders. (nicerx.com)
  • [3] It is a predictable consequence of excess serotonin on the central nervous system . (wikipedia.org)