One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.
One of the endogenous pentapeptides with morphine-like activity. It differs from LEU-ENKEPHALIN by the amino acid METHIONINE in position 5. Its first four amino acid sequence is identical to the tetrapeptide sequence at the N-terminal of BETA-ENDORPHIN.
One of the endogenous pentapeptides with morphine-like activity. It differs from MET-ENKEPHALIN in the LEUCINE at position 5. Its first four amino acid sequence is identical to the tetrapeptide sequence at the N-terminal of BETA-ENDORPHIN.
An enkephalin analog that selectively binds to the MU OPIOID RECEPTOR. It is used as a model for drug permeability experiments.
A delta-selective opioid (ANALGESICS, OPIOID). It can cause transient depression of mean arterial blood pressure and heart rate.
A disulfide opioid pentapeptide that selectively binds to the DELTA OPIOID RECEPTOR. It possesses antinociceptive activity.
One of the three major groups of endogenous opioid peptides. They are large peptides derived from the PRO-OPIOMELANOCORTIN precursor. The known members of this group are alpha-, beta-, and gamma-endorphin. The term endorphin is also sometimes used to refer to all opioid peptides, but the narrower sense is used here; OPIOID PEPTIDES is used for the broader group.
Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.
A class of opioid receptors recognized by its pharmacological profile. Delta opioid receptors bind endorphins and enkephalins with approximately equal affinity and have less affinity for dynorphins.
A class of opioid receptors recognized by its pharmacological profile. Mu opioid receptors bind, in decreasing order of affinity, endorphins, dynorphins, met-enkephalin, and leu-enkephalin. They have also been shown to be molecular receptors for morphine.
A specific opiate antagonist that has no agonist activity. It is a competitive antagonist at mu, delta, and kappa opioid receptors.
A class of opioid peptides including dynorphin A, dynorphin B, and smaller fragments of these peptides. Dynorphins prefer kappa-opioid receptors (RECEPTORS, OPIOID, KAPPA) and have been shown to play a role as central nervous system transmitters.
A kappa opioid receptor agonist. The compound has analgesic action and shows positive inotropic effects on the electrically stimulated left atrium. It also affects various types of behavior in mammals such as locomotion, rearing, and grooming.
An analgesic with mixed narcotic agonist-antagonist properties.
Agents inhibiting the effect of narcotics on the central nervous system.
The principal alkaloid in opium and the prototype opiate analgesic and narcotic. Morphine has widespread effects in the central nervous system and on smooth muscle.
A ZINC-containing exopeptidase primarily found in SECRETORY VESICLES of endocrine and neuroendocrine cells. It catalyzes the cleavage of C-terminal ARGININE or LYSINE residues from polypeptides and is active in processing precursors of PEPTIDE HORMONES and other bioactive peptides.
Morphine derivatives of the methanobenzazocine family that act as potent analgesics.
Derivative of noroxymorphone that is the N-cyclopropylmethyl congener of NALOXONE. It is a narcotic antagonist that is effective orally, longer lasting and more potent than naloxone, and has been proposed for the treatment of heroin addiction. The FDA has approved naltrexone for the treatment of alcohol dependence.
A stable synthetic analog of methionine enkephalin (ENKEPHALIN, METHIONINE). Actions are similar to those of methionine enkephalin. Its effects can be reversed by narcotic antagonists such as naloxone.
A 31-amino acid peptide that is the C-terminal fragment of BETA-LIPOTROPIN. It acts on OPIOID RECEPTORS and is an analgesic. Its first four amino acids at the N-terminal are identical to the tetrapeptide sequence of METHIONINE ENKEPHALIN and LEUCINE ENKEPHALIN.
Compounds with activity like OPIATE ALKALOIDS, acting at OPIOID RECEPTORS. Properties include induction of ANALGESIA or NARCOSIS.
A class of opioid receptors recognized by its pharmacological profile. Kappa opioid receptors bind dynorphins with a higher affinity than endorphins which are themselves preferred to enkephalins.
The endogenous peptides with opiate-like activity. The three major classes currently recognized are the ENKEPHALINS, the DYNORPHINS, and the ENDORPHINS. Each of these families derives from different precursors, proenkephalin, prodynorphin, and PRO-OPIOMELANOCORTIN, respectively. There are also at least three classes of OPIOID RECEPTORS, but the peptide families do not map to the receptors in a simple way.
A narcotic antagonist similar in action to NALOXONE. It is used to remobilize animals after ETORPHINE neuroleptanalgesia and is considered a specific antagonist to etorphine.
Agents that induce NARCOSIS. Narcotics include agents that cause somnolence or induced sleep (STUPOR); natural or synthetic derivatives of OPIUM or MORPHINE or any substance that has such effects. They are potent inducers of ANALGESIA and OPIOID-RELATED DISORDERS.
A narcotic analgesic morphinan used as a sedative in veterinary practice.
A potent inhibitor of membrane metalloendopeptidase (ENKEPHALINASE). Thiorphan potentiates morphine-induced ANALGESIA and attenuates naloxone-precipitated withdrawal symptoms.
Peptides composed of between two and twelve amino acids.
Compounds capable of relieving pain without the loss of CONSCIOUSNESS.
Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification, such as cleavage, to produce the active functional protein or peptide hormone.
Compounds based on a partially saturated iminoethanophenanthrene, which can be described as ethylimino-bridged benzo-decahydronaphthalenes. They include some of the OPIOIDS found in PAPAVER that are used as ANALGESICS.
Sulfhydryl acylated derivative of GLYCINE.
Enzyme that is a major constituent of kidney brush-border membranes and is also present to a lesser degree in the brain and other tissues. It preferentially catalyzes cleavage at the amino group of hydrophobic residues of the B-chain of insulin as well as opioid peptides and other biologically active peptides. The enzyme is inhibited primarily by EDTA, phosphoramidon, and thiorphan and is reactivated by zinc. Neprilysin is identical to common acute lymphoblastic leukemia antigen (CALLA Antigen), an important marker in the diagnosis of human acute lymphocytic leukemia. There is no relationship with CALLA PLANT.
The inner portion of the adrenal gland. Derived from ECTODERM, adrenal medulla consists mainly of CHROMAFFIN CELLS that produces and stores a number of NEUROTRANSMITTERS, mainly adrenaline (EPINEPHRINE) and NOREPINEPHRINE. The activity of the adrenal medulla is regulated by the SYMPATHETIC NERVOUS SYSTEM.
Pyrrolidines are saturated, heterocyclic organic compounds containing a five-membered ring with four carbon atoms and one nitrogen atom (NRCH2CH2), commonly found as structural components in various alkaloids and used in the synthesis of pharmaceuticals and other organic materials.
Organelles in CHROMAFFIN CELLS located in the adrenal glands and various other organs. These granules are the site of the synthesis, storage, metabolism, and secretion of EPINEPHRINE and NOREPINEPHRINE.
The representation of the phylogenetically oldest part of the corpus striatum called the paleostriatum. It forms the smaller, more medial part of the lentiform nucleus.
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.
A 14-amino acid peptide named for its ability to inhibit pituitary GROWTH HORMONE release, also called somatotropin release-inhibiting factor. It is expressed in the central and peripheral nervous systems, the gut, and other organs. SRIF can also inhibit the release of THYROID-STIMULATING HORMONE; PROLACTIN; INSULIN; and GLUCAGON besides acting as a neurotransmitter and neuromodulator. In a number of species including humans, there is an additional form of somatostatin, SRIF-28 with a 14-amino acid extension at the N-terminal.
The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
Progressive diminution of the susceptibility of a human or animal to the effects of a drug, resulting from its continued administration. It should be differentiated from DRUG RESISTANCE wherein an organism, disease, or tissue fails to respond to the intended effectiveness of a chemical or drug. It should also be differentiated from MAXIMUM TOLERATED DOSE and NO-OBSERVED-ADVERSE-EFFECT LEVEL.
A semisynthetic analgesic used in the study of narcotic receptors.
The excretory duct of the testes that carries SPERMATOZOA. It rises from the SCROTUM and joins the SEMINAL VESICLES to form the ejaculatory duct.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.
Injections into the cerebral ventricles.
Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.
Compounds containing the PhCH= radical.
Introduction of therapeutic agents into the spinal region using a needle and syringe.
Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue.
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.
One of two ganglionated neural networks which together form the ENTERIC NERVOUS SYSTEM. The myenteric (Auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (From FASEB J 1989;3:127-38)
Bluish-colored region in the superior angle of the FOURTH VENTRICLE floor, corresponding to melanin-like pigmented nerve cells which lie lateral to the PERIAQUEDUCTAL GRAY.
Analogs or derivatives of morphine.
Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.
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.
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.
A common neoplasm of early childhood arising from neural crest cells in the sympathetic nervous system, and characterized by diverse clinical behavior, ranging from spontaneous remission to rapid metastatic progression and death. This tumor is the most common intraabdominal malignancy of childhood, but it may also arise from thorax, neck, or rarely occur in the central nervous system. Histologic features include uniform round cells with hyperchromatic nuclei arranged in nests and separated by fibrovascular septa. Neuroblastomas may be associated with the opsoclonus-myoclonus syndrome. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2099-2101; Curr Opin Oncol 1998 Jan;10(1):43-51)
The relationship between the dose of an administered drug and the response of the organism to the drug.
Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).
The cells of the body which stain with chromium salts. They occur along the sympathetic nerves, in the adrenal gland, and in various other organs.
Dull or sharp aching pain caused by stimulated NOCICEPTORS due to tissue injury, inflammation or diseases. It can be divided into somatic or tissue pain and VISCERAL PAIN.
A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.
A neuropeptide of 29-30 amino acids depending on the species. Galanin is widely distributed throughout the BRAIN; SPINAL CORD; and INTESTINES. There are various subtypes of GALANIN RECEPTORS implicating roles of galanin in regulating FOOD INTAKE; pain perception; memory; and other neuroendocrine functions.
Gelatinous-appearing material in the dorsal horn of the spinal cord, consisting chiefly of Golgi type II neurons and some larger nerve cells.
Use of electric potential or currents to elicit biological responses.

Dynorphin A processing enzyme: tissue distribution, isolation, and characterization. (1/1136)

Limited proteolysis of the dynorphin precursor (prodynorphin) at dibasic and monobasic processing sites results in the generation of bioactive dynorphins. In the brain and neurointermediate lobe of the pituitary, prodynorphin is processed to produce alpha and beta neo endorphins, dynorphins (Dyn) A-17 and Dyn A-8, Dyn B-13, and leucine-enkephalin. The formation of Dyn A-8 from Dyn A-17 requires a monobasic cleavage between Ile and Arg. We have identified an enzymatic activity capable of processing at this monobasic site in the rat brain and neurointermediate lobe of the bovine pituitary; this enzyme is designated "dynorphin A-17 processing enzyme." In the rat brain and neurointermediate lobe, a majority of the Dyn A processing enzyme activity is membrane-associated and can be released by treatment with 1% Triton X-100. This enzyme has been purified to apparent homogeneity from the membrane extract of the neurointermediate lobe using preparative iso-electrofocussing in a granulated gel pH 3.5 to 10, FPLC using anion exchange chromatography, and non-denaturing electrophoresis. The Dyn A processing enzyme exhibits a pI of about 5.8 and a molecular mass of about 65 kDa under reducing conditions. The Dyn A processing enzyme is a metalloprotease and has a neutral pH optimum. It exhibits substantial sensitivity to metal chelating agents and thiol agents suggesting that this enzyme is a thiol-sensitive metalloprotease. Specific inhibitors of other metallopeptidases such as enkephalinase [EC 3.4.24.11], the enkephalin generating neutral endopeptidase [EC 3.4.24.15], or NRD convertase do not inhibit the Dyn A processing enzyme activity. In contrast, specific inhibitors of angiotensin converting enzyme inhibit the activity. The purified enzyme is able to process a number of neuropeptides at both monobasic and dibasic sites. These characteristics are consistent with a role for the Dyn A processing enzyme in the processing of Dyn A-17 and other neuropeptides in the brain.  (+info)

Binding properties of C-truncated delta opioid receptors. (2/1136)

AIM: To study the role of C-terminal delta opioid receptor involved in ligand binding affinity and selectivity. METHODS: The 31 amino acid residues of C-terminal truncated delta opioid receptors and the wild-type were expressed stably in Chinese hamster ovary (CHO) cells, respectively. Then the ligand binding properties of the products were studied by receptor binding assay. RESULTS: A typical mutated receptor clone CHO-T and a wild-type receptor clone CHO-W were obtained. The Kd values of [3H] diprenorphine (Dip) and [3H]leucine-2-alanine enkephalin (DADLE) bound to CHO-T were similar to CHO-W. Both the specific [3H]Dip bindings of CHO-T and CHO-W were strongly inhibited by delta selective agonists with similar Ki, but neither by mu nor kappa selective agonists. CONCLUSION: The C-terminal of the delta opioid receptor is not involved in the ligands binding affinity and selectivity.  (+info)

Absence of G-protein activation by mu-opioid receptor agonists in the spinal cord of mu-opioid receptor knockout mice. (3/1136)

1. The ability of mu-opioid receptor agonists to activate G-proteins in the spinal cord of mu-opioid receptor knockout mice was examined by monitoring the binding to membranes of the non-hydrolyzable analogue of GTP, guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPgammaS). 2. In the receptor binding study, Scatchard analysis of [3H][D-Ala2,NHPhe4,Gly-ol]enkephalin ([3H]DAMGO; mu-opioid receptor ligand) binding revealed that the heterozygous mu-knockout mice displayed approximately 40% reduction in the number of mu-receptors as compared to the wild-type mice. The homozygous mu-knockout mice showed no detectable mu-binding sites. 3. The newly isolated mu-opioid peptides endomorphin-1 and -2, the synthetic selective mu-opioid receptor agonist DAMGO and the prototype of mu-opioid receptor agonist morphine each produced concentration-dependent increases in [35S]GTPgammaS binding in wild-type mice. This stimulation was reduced by 55-70% of the wild-type level in heterozygous, and virtually eliminated in homozygous knockout mice. 4. No differences in the [35S]GTPgammaS binding stimulated by specific delta1- ([D-Pen2,5]enkephalin), delta2-([D-Ala2]deltorphin II) or kappa1-(U50,488H) opioid receptor agonists were noted in mice of any of the three genotypes. 5. The data clearly indicate that mu-opioid receptor gene products play a key role in G-protein activation by endomorphins, DAMGO and morphine in the mouse spinal cord. They support the idea that mu-opioid receptor densities could be rate-limiting steps in the G-protein activation by mu-opioid receptor agonists in the spinal cord. These thus indicate a limited physiological mu-receptor reserve. Furthermore, little change in delta1-, delta2- or kappa1-opioid receptor-G-protein complex appears to accompany mu-opioid receptor gene deletions in this region.  (+info)

Antihyperalgesic effects of infection with a preproenkephalin-encoding herpes virus. (4/1136)

To test the utility of gene therapeutic approaches for the treatment of pain, a recombinant herpes simplex virus, type 1, has been engineered to contain the cDNA for an opioid peptide precursor, human preproenkephalin, under control of the human cytomegalovirus promoter. This virus and a similar recombinant containing the Escherichia coli lacZ gene were applied to the abraded skin of the dorsal hindpaw of mice. After infection, the presence of beta-galactosidase in neuronal cell bodies of the relevant spinal ganglia (lacZ-containing virus) and of human proenkephalin (preproenkephalin-encoding virus) in the central terminals of these neurons indicated appropriate gene delivery and expression. Baseline foot withdrawal responses to noxious radiant heat mediated by Adelta and C fibers were similar in animals infected with proenkephalin-encoding and beta-galactosidase-encoding viruses. Sensitization of the foot withdrawal response after application of capsaicin (C fibers) or dimethyl sulfoxide (Adelta fibers) observed in control animals was reduced or eliminated in animals infected with the proenkephalin-encoding virus for at least 7 weeks postinfection. Hence, preproenkephalin cDNA delivery selectively blocked hyperalgesia without disrupting baseline sensory neurotransmission. This blockade of sensitization was reversed by administration of the opioid antagonist naloxone, apparently acting in the spinal cord. The results demonstrate that the function of sensory neurons can be selectively altered by viral delivery of a transgene. Because hyperalgesic mechanisms may be important in establishing and maintaining neuropathic and other chronic pain states, this approach may be useful for treatment of chronic pain and hyperalgesia in humans.  (+info)

Nitrocinnamoyl and chlorocinnamoyl derivatives of dihydrocodeinone: in vivo and in vitro characterization of mu-selective agonist and antagonist activity. (5/1136)

Two 14beta-p-nitrocinnamoyl derivatives of dihydrocodeinone, 14beta-(p-nitrocinnamoylamino)-7,8-dihydrocodeinone (CACO) and N-cyclopropylmethylnor-14beta-(p-nitrocinnamoylamino)- 7, 8-dihydrocodeinone (N-CPM-CACO), and the corresponding chlorocinnamoylamino analogs, 14beta-(p-chlorocinnamoylamino)-7, 8-dihydrocodeinone (CAM) and N-cyclopropylmethylnor-14beta-(p-chlorocinnamoylamino) -7, 8-dihydrocodeinone (MC-CAM), were tested in opioid receptor binding assays and the mouse tail-flick test to characterize the opioid affinity, selectivity, and antinociceptive properties of these compounds. In competition binding assays, all four compounds bound to the mu opioid receptor with high affinity. When bovine striatal membranes were incubated with any of the four dihydrocodeinones, binding to the mu receptor was inhibited in a concentration-dependent, wash-resistant manner. Saturation binding experiments demonstrated that the wash-resistant inhibition of mu binding was due to a decrease in the Bmax value for the binding of the mu-selective peptide [3H][D-Ala2, MePhe4,Gly(ol)5] enkephalin and not a change in the Kd value, suggesting an irreversible interaction of the compounds with the mu receptor. In the mouse 55 degrees C warm water tail-flick test, both CACO and N-CPM-CACO acted as short-term mu-selective agonists when administered by i. c.v. injection, whereas CAM and MC-CAM produced no measurable antinociception at doses up to 30 nmol. Pretreatment of mice for 24 h with any of the four dihydrocodeinone derivatives produced a dose-dependent antagonism of antinociception mediated by the mu but not the delta or kappa receptors. Long-term antagonism of morphine-induced antinociception lasted for at least 48 h after i.c. v. administration. Finally, shifts in the morphine dose-response lines after 24-h pretreatment with the four dihydrocodeinone compounds suggest that the nitrocinnamoylamino derivatives may produce a greater magnitude long-term antagonism of morphine-induced antinociception than the chlorocinnamoylamino analogs.  (+info)

Effect of phosducin on opioid receptor function. (6/1136)

Phosducin (Phd) regulates the function of G proteins by its ability to tightly bind Gbetagamma subunits. Because the internalization of opioid receptors as well as the activity of adenylyl cyclase (AC) activity depends on G proteins, we tested Phd on these parameters. NG 108-15 hybrid cells stably expressing the phosphoprotein were challenged with [D-penicillamine2,D-penicillamine5]enkephalin to inhibit cAMP generation, demonstrating an increased efficacy of the opioid on AC. Studying the binding of [35S]guanosine-5'-O-(gamma-thio)-triphosphate to membranes from Phd overexpressing cells, we found that [D-penicillamine2, D-penicillamine5 ]enkephalin failed, in the presence of Phd (0.1 nM), to elevate incorporation of the nucleotide. Phd also strongly inhibited opioid-stimulated GTPase activity. NG 108-15 cells were also employed to investigate the effect of Phd on opioid receptor internalization. Control cells and cells overexpressing Phd were transiently transfected to express mu-opioid receptors fused to green fluorescence protein. In controls and in Phd overexpressing cells confocal microscopy identified fluorescence associated with the membrane. Time-lapse series microscopy of living control cells challenged with etorphine (1 microM) revealed receptor internalization within 30 min. In contrast, Phd overexpressing cells largely failed to respond to the opioid. Thus, in Phd overexpressing cells, opioids exhibit an increased efficacy despite the inhibitory action of the phosphoprotein on opioid-stimulated incorporation of [35S]guanosine-5'-O-(gamma-thio)-triphosphate. We suggest that inhibition of GTPase stabilizes the opioid-induced G protein Gi-GTP complex, which is believed to enhance AC inhibition. Finally, scavenging of Gbetagamma by Phd attenuates internalization of opioid receptors, which may contribute to the efficacy of opioids.  (+info)

The absence of a direct correlation between the loss of [D-Ala2, MePhe4,Gly5-ol]Enkephalin inhibition of adenylyl cyclase activity and agonist-induced mu-opioid receptor phosphorylation. (7/1136)

Chronic activation of the mu-opioid receptor (MOR1TAG) results in the loss of agonist response that has been attributed to desensitization and down-regulation of the receptor. It has been suggested that opioid receptor phosphorylation is the mechanism by which this desensitization and down-regulation occurs. When MOR1TAG was stably expressed in both neuroblastoma neuro2A and human embryonic kidney HEK293 cells, the opioid agonist [D-Ala2,MePhe4, Gly5-ol]enkephalin (DAMGO) induced a time- and concentration-dependent phosphorylation of the receptor, in both cell lines, that could be reversed by the antagonist naloxone. Protein kinase C can phosphorylate the receptor, but is not involved in DAMGO-induced MOR1TAG phosphorylation. The rapid rate of receptor phosphorylation, occurring within minutes, did not correlate with the rate of the loss of agonist-mediated inhibition of adenylyl cyclase, which occurs in hours. This lack of correlation between receptor phosphorylation and the loss of response was further demonstrated when receptor phosphorylation was increased by either calyculin A or overexpression of the G-protein receptor kinases. Calyculin A increased the magnitude of MOR1TAG phosphorylation without altering the DAMGO-induced loss of the adenylyl cyclase response. Similarly, when mu- and delta-opioid (DOR1TAG) receptors were expressed in the same system, overexpression of beta-adrenergic receptor kinase 2 elevated agonist-induced phosphorylation for both receptors. However, in the same cell lines under the same conditions, overexpression of beta-adrenergic receptor kinase 2 and beta-arrestin 2 accelerated the rate of DPDPE- but not DAMGO-induced receptor desensitization. Thus, these data show that phosphorylation of MOR1TAG is not an obligatory event for the DAMGO-induced loss in the adenylyl cyclase regulation by the receptor.  (+info)

Antagonism by acetyl-RYYRIK-NH2 of G protein activation in rat brain preparations and of chronotropic effect on rat cardiomyocytes evoked by nociceptin/orphanin FQ. (8/1136)

For the further elucidation of the central functions of nociceptin/orphanin FQ (noc/OFQ), the endogenous ligand of the G protein-coupled opioid receptor-like receptor ORL1, centrally acting specific antagonists will be most helpful. In this study it was found that the hexapeptide acetyl-RYYRIK-NH2 (Ac-RYYRIK-NH2), described in literature as partial agonist on ORL1 transfected in CHO cells, antagonizes the stimulation of [35S]-GTPgammaS binding to G proteins by noc/OFQ in membranes and sections of rat brain. The antagonism of the peptide was competitive, of high affinity (Schild constant 6.58 nM), and specific for noc/OFQ in that the stimulation of GTP binding by agonists for the mu-, delta-, and kappa-opioid receptor was not inhibited. The hexapeptide also fully inhibited the chronotropic effect of noc/OFQ on neonatal rat cardiomyocytes. It is suggested that Ac-RYYRIK-NH2 may provide a promising starting point for in vivo tests for antagonism of the action of noc/OFQ and for the further development of highly active and specific antagonists.  (+info)

Enkephalins are naturally occurring opioid peptides that bind to opiate receptors in the brain and other organs, producing pain-relieving and other effects. They are derived from the precursor protein proenkephalin and consist of two main types: Leu-enkephalin and Met-enkephalin. Enkephalins play a role in pain modulation, stress response, mood regulation, and addictive behaviors. They are also involved in the body's reward system and have been implicated in various physiological processes such as respiration, gastrointestinal motility, and hormone release.

Enkephalins are naturally occurring opioid peptides in the body that bind to opiate receptors and help reduce pain and produce a sense of well-being. There are two major types of enkephalins: Leu-enkephalin and Met-enkephalin, which differ by only one amino acid at the N-terminus.

Methionine-enkephalin (Met-enkephalin) is a type of enkephalin that contains methionine as its N-terminal amino acid. Its chemical formula is Tyr-Gly-Gly-Phe-Met, and it is derived from the precursor protein proenkephalin. Met-enkephalin has a shorter half-life than Leu-enkephalin due to its susceptibility to enzymatic degradation by aminopeptidases.

Met-enkephalin plays an essential role in pain modulation, reward processing, and addiction. It is also involved in various physiological functions, including respiration, cardiovascular regulation, and gastrointestinal motility. Dysregulation of enkephalins has been implicated in several pathological conditions, such as chronic pain, drug addiction, and neurodegenerative disorders.

Enkephalins are naturally occurring opioid peptides in the body that bind to opiate receptors and help reduce pain and produce a sense of well-being. There are two major types of enkephalins: Met-enkephalin and Leu-enkephalin, which differ by only one amino acid at position 5 (Leucine or Methionine).

Leu-enkephalin, also known as YGGFL, is a type of enkephalin that contains the amino acids Tyrosine (Y), Glycine (G), Glycine (G), Phenylalanine (F), and Leucine (L) in its sequence. It is involved in pain regulation, mood, and other physiological processes.

Leu-enkephalin is synthesized from a larger precursor protein called proenkephalin and is stored in the secretory vesicles of neurons. When released into the synaptic cleft, Leu-enkephalin can bind to opioid receptors on neighboring cells, leading to various physiological responses.

Leu-enkephalin has a shorter half-life than Met-enkephalin due to its susceptibility to enzymatic degradation by peptidases. However, it still plays an essential role in modulating pain and other functions in the body.

Enkephalins are naturally occurring opioid peptides in the body that bind to opiate receptors and help reduce pain and produce a sense of well-being. There are several different types of enkephalins, including Leu-enkephalin and Met-enkephalin, which differ based on their amino acid sequence.

Leucine-enkephalin (Leu-Enk) is a specific type of enkephalin that contains the amino acids tyrosine, glycine, glutamic acid, leucine, and methionine in its sequence. The Leucine-2-Alanine variant of Leu-Enk refers to a synthetic form of this peptide where the leucine at position 2 is replaced with alanine. This modification can affect the stability, activity, and pharmacological properties of the enkephalin molecule.

It's important to note that while Leu-Enk and its analogs have potential therapeutic applications in pain management, they are also subject to abuse and addiction due to their opioid properties. Therefore, their use is tightly regulated and requires careful medical supervision.

Endorphins are a type of neurotransmitter, which are chemicals that transmit signals in the nervous system and brain. The term "endorphin" comes from "endogenous morphine," reflecting the fact that these substances are produced naturally within the body and have effects similar to opiate drugs like morphine.

Endorphins are released in response to stress or pain, but they also occur naturally during exercise, excitement, laughter, love, and orgasm. They work by interacting with the opiate receptors in the brain to reduce the perception of pain and promote feelings of pleasure and well-being. Endorphins also play a role in regulating various physiological processes, including appetite, mood, and sleep.

In summary, endorphins are natural painkillers and mood elevators produced by the body in response to stress, pain, or enjoyable activities.

Opioid receptors are a type of G protein-coupled receptor (GPCR) found in the cell membranes of certain neurons in the central and peripheral nervous system. They bind to opioids, which are chemicals that can block pain signals and produce a sense of well-being. There are four main types of opioid receptors: mu, delta, kappa, and nociceptin. These receptors play a role in the regulation of pain, reward, addiction, and other physiological functions. Activation of opioid receptors can lead to both therapeutic effects (such as pain relief) and adverse effects (such as respiratory depression and constipation).

Opioid delta receptors, also known as delta opioid receptors (DORs), are a type of G protein-coupled receptor found in the nervous system and other tissues throughout the body. They belong to the opioid receptor family, which includes mu, delta, and kappa receptors. These receptors play an essential role in pain modulation, reward processing, and addictive behaviors.

Delta opioid receptors are activated by endogenous opioid peptides such as enkephalins and exogenous opioids like synthetic drugs. Once activated, they trigger a series of intracellular signaling events that can lead to inhibition of neuronal excitability, reduced neurotransmitter release, and ultimately, pain relief.

Delta opioid receptors have also been implicated in various physiological processes, including immune function, respiratory regulation, and gastrointestinal motility. However, their clinical use as therapeutic targets has been limited due to the development of tolerance and potential adverse effects such as sedation and respiratory depression.

In summary, delta opioid receptors are a type of opioid receptor that plays an essential role in pain modulation and other physiological processes. They are activated by endogenous and exogenous opioids and trigger intracellular signaling events leading to various effects, including pain relief. However, their clinical use as therapeutic targets is limited due to potential adverse effects.

Opioid mu receptors, also known as mu-opioid receptors (MORs), are a type of G protein-coupled receptor that binds to opioids, a class of chemicals that include both natural and synthetic painkillers. These receptors are found in the brain, spinal cord, and gastrointestinal tract, and play a key role in mediating the effects of opioid drugs such as morphine, heroin, and oxycodone.

MORs are involved in pain modulation, reward processing, respiratory depression, and physical dependence. Activation of MORs can lead to feelings of euphoria, decreased perception of pain, and slowed breathing. Prolonged activation of these receptors can also result in tolerance, where higher doses of the drug are required to achieve the same effect, and dependence, where withdrawal symptoms occur when the drug is discontinued.

MORs have three main subtypes: MOR-1, MOR-2, and MOR-3, with MOR-1 being the most widely studied and clinically relevant. Selective agonists for MOR-1, such as fentanyl and sufentanil, are commonly used in anesthesia and pain management. However, the abuse potential and risk of overdose associated with these drugs make them a significant public health concern.

Naloxone is a medication used to reverse the effects of opioids, both illicit and prescription. It works by blocking the action of opioids on the brain and restoring breathing in cases where opioids have caused depressed respirations. Common brand names for naloxone include Narcan and Evzio.

Naloxone is an opioid antagonist, meaning that it binds to opioid receptors in the body without activating them, effectively blocking the effects of opioids already present at these sites. It has no effect in people who have not taken opioids and does not reverse the effects of other sedatives or substances.

Naloxone can be administered via intranasal, intramuscular, intravenous, or subcutaneous routes. The onset of action varies depending on the route of administration but generally ranges from 1 to 5 minutes when given intravenously and up to 10-15 minutes with other methods.

The duration of naloxone's effects is usually shorter than that of most opioids, so multiple doses or a continuous infusion may be necessary in severe cases to maintain reversal of opioid toxicity. Naloxone has been used successfully in emergency situations to treat opioid overdoses and has saved many lives.

It is important to note that naloxone does not reverse the effects of other substances or address the underlying causes of addiction, so it should be used as part of a comprehensive treatment plan for individuals struggling with opioid use disorders.

Dynorphins are a type of opioid peptide that is naturally produced in the body. They bind to specific receptors in the brain, known as kappa-opioid receptors, and play a role in modulating pain perception, emotional response, and reward processing. Dynorphins are derived from a larger precursor protein called prodynorphin and are found throughout the nervous system, including in the spinal cord, brainstem, and limbic system. They have been implicated in various physiological processes, as well as in the development of certain neurological and psychiatric disorders, such as chronic pain, depression, and substance use disorders.

Ethylketocyclazocine is a synthetic opioid drug that acts as a potent mixed agonist-antagonist at mu, kappa, and delta opioid receptors. It produces analgesic, sedative, and respiratory depressant effects, but its clinical use is limited due to its strong dysphoric and hallucinogenic properties. Ethylketocyclazocine is primarily used in research to study the pharmacology of opioid receptors and their roles in pain modulation, addiction, and other physiological processes.

Cyclazocine is a synthetic opioid drug that acts as a partial agonist at mu and kappa opioid receptors, and as an antagonist at delta opioid receptors. It has analgesic (pain-relieving) effects, but its use as an analgesic is limited due to its potential for abuse and the occurrence of unpleasant psychotomimetic side effects such as dysphoria, delusions, and hallucinations.

Cyclazocine was first synthesized in 1957 and has been studied for its potential use in the treatment of opioid addiction, but it is not currently approved for medical use in many countries, including the United States. It is classified as a Schedule I controlled substance in the US, indicating that it has a high potential for abuse and no accepted medical use.

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.

Morphine is a potent opioid analgesic (pain reliever) derived from the opium poppy. It works by binding to opioid receptors in the brain and spinal cord, blocking the transmission of pain signals and reducing the perception of pain. Morphine is used to treat moderate to severe pain, including pain associated with cancer, myocardial infarction, and other conditions. It can also be used as a sedative and cough suppressant.

Morphine has a high potential for abuse and dependence, and its use should be closely monitored by healthcare professionals. Common side effects of morphine include drowsiness, respiratory depression, constipation, nausea, and vomiting. Overdose can result in respiratory failure, coma, and death.

Carboxypeptidase H is also known as carboxypeptidase E or CPE. It is an enzyme that plays a role in the processing and activation of neuropeptides, which are small protein-like molecules that function as chemical messengers within the nervous system. Carboxypeptidase H/E is responsible for removing certain amino acids from the end of newly synthesized neuropeptides, allowing them to become biologically active. It is widely expressed in the brain and other tissues throughout the body.

Benzomorphans are a class of opioid drugs that have a chemical structure similar to morphine. They are synthetic compounds, meaning they are made in a laboratory and do not occur naturally. Benzomorphans include drugs such as pentazocine and phenazocine, which are used for pain relief and cough suppression. These drugs work by binding to opioid receptors in the brain and spinal cord, which helps to reduce the perception of pain and suppress coughing.

Benzomorphans have a unique chemical structure that differs from other opioids such as morphine or fentanyl. They are classified as "mixed agonist-antagonists," meaning they can act as both an agonist (a substance that binds to a receptor and activates it) and an antagonist (a substance that binds to a receptor but does not activate it, and may block the effects of other substances that do activate the receptor). This property makes benzomorphans useful for pain relief in certain situations, as they can provide pain relief without causing some of the side effects associated with other opioids, such as respiratory depression.

However, like all opioid drugs, benzomorphans carry a risk of addiction and dependence, and can cause serious harm or even death if taken in large doses or mixed with other substances that depress the central nervous system. It is important to use these medications only as directed by a healthcare provider and to follow their instructions carefully.

Naltrexone is a medication that is primarily used to manage alcohol dependence and opioid dependence. It works by blocking the effects of opioids and alcohol on the brain, reducing the euphoric feelings and cravings associated with their use. Naltrexone comes in the form of a tablet that is taken orally, and it has no potential for abuse or dependence.

Medically, naltrexone is classified as an opioid antagonist, which means that it binds to opioid receptors in the brain without activating them, thereby blocking the effects of opioids such as heroin, morphine, and oxycodone. It also reduces the rewarding effects of alcohol by blocking the release of endorphins, which are natural chemicals in the brain that produce feelings of pleasure.

Naltrexone is often used as part of a comprehensive treatment program for addiction, along with counseling, behavioral therapy, and support groups. It can help individuals maintain abstinence from opioids or alcohol by reducing cravings and preventing relapse. Naltrexone is generally safe and well-tolerated, but it may cause side effects such as nausea, headache, dizziness, and fatigue in some people.

It's important to note that naltrexone should only be used under the supervision of a healthcare provider, and it is not recommended for individuals who are currently taking opioids or who have recently stopped using them, as it can cause withdrawal symptoms. Additionally, naltrexone may interact with other medications, so it's important to inform your healthcare provider of all medications you are taking before starting naltrexone therapy.

Beta-endorphins are naturally occurring opioid peptides that are produced in the brain and other parts of the body. They are synthesized from a larger precursor protein called proopiomelanocortin (POMC) and consist of 31 amino acids. Beta-endorphins have potent analgesic effects, which means they can reduce the perception of pain. They also play a role in regulating mood, emotions, and various physiological processes such as immune function and hormonal regulation.

Beta-endorphins bind to opioid receptors in the brain and other tissues, leading to a range of effects including pain relief, sedation, euphoria, and reduced anxiety. They are released in response to stress, physical activity, and certain physiological conditions such as pregnancy and lactation. Beta-endorphins have been studied for their potential therapeutic uses in the treatment of pain, addiction, and mood disorders. However, more research is needed to fully understand their mechanisms of action and potential side effects.

Analgesics, opioid are a class of drugs used for the treatment of pain. They work by binding to specific receptors in the brain and spinal cord, blocking the transmission of pain signals to the brain. Opioids can be synthetic or natural, and include drugs such as morphine, codeine, oxycodone, hydrocodone, hydromorphone, fentanyl, and methadone. They are often used for moderate to severe pain, such as that resulting from injury, surgery, or chronic conditions like cancer. However, opioids can also produce euphoria, physical dependence, and addiction, so they are tightly regulated and carry a risk of misuse.

Opioid receptors, also known as opiate receptors, are a type of G protein-coupled receptor found in the nervous system and other tissues. They are activated by endogenous opioid peptides, as well as exogenous opiates and opioids. There are several subtypes of opioid receptors, including mu, delta, and kappa.

Kappa opioid receptors (KORs) are a subtype of opioid receptor that are widely distributed throughout the body, including in the brain, spinal cord, and gastrointestinal tract. They are activated by endogenous opioid peptides such as dynorphins, as well as by synthetic and semi-synthetic opioids such as salvinorin A and U-69593.

KORs play a role in the modulation of pain, mood, and addictive behaviors. Activation of KORs has been shown to produce analgesic effects, but can also cause dysphoria, sedation, and hallucinations. KOR agonists have potential therapeutic uses for the treatment of pain, addiction, and other disorders, but their use is limited by their side effects.

It's important to note that opioid receptors and their ligands (drugs or endogenous substances that bind to them) are complex systems with many different actions and effects in the body. The specific effects of KOR activation depend on a variety of factors, including the location and density of the receptors, the presence of other receptors and signaling pathways, and the dose and duration of exposure to the ligand.

Opioid peptides are naturally occurring short chains of amino acids in the body that bind to opioid receptors in the brain, spinal cord, and gut, acting in a similar way to opiate drugs like morphine or heroin. They play crucial roles in pain regulation, reward systems, and addictive behaviors. Some examples of opioid peptides include endorphins, enkephalins, and dynorphins. These substances are released in response to stress, physical exertion, or injury and help modulate the perception of pain and produce feelings of pleasure or euphoria.

Diprenorphine is a potent opioid antagonist, which is used primarily in veterinary medicine as an antidote for overdoses of opioid drugs or accidents involving exposure to opioids in wildlife. It works by blocking the effects of opioids on the brain and reversing their potentially harmful or deadly symptoms, such as respiratory depression, sedation, and decreased heart rate.

Diprenorphine is a non-selective antagonist at mu, delta, and kappa opioid receptors, which means it can reverse the effects of all three types of opioid receptors in the body. It has a high affinity for these receptors, making it a very effective antidote for opioid overdoses.

In human medicine, diprenorphine is not commonly used due to its short duration of action and the availability of other longer-acting opioid antagonists such as naloxone. However, it may be used in some specialized medical settings, such as in the management of opioid toxicity during anesthesia or in cases where a longer-acting antagonist is not available.

It's important to note that diprenorphine should only be administered under the supervision of a trained medical professional, as improper use can lead to serious adverse effects or even death.

Narcotics, in a medical context, are substances that induce sleep, relieve pain, and suppress cough. They are often used for anesthesia during surgical procedures. Narcotics are derived from opium or its synthetic substitutes and include drugs such as morphine, codeine, fentanyl, oxycodone, and hydrocodone. These drugs bind to specific receptors in the brain and spinal cord, reducing the perception of pain and producing a sense of well-being. However, narcotics can also produce physical dependence and addiction, and their long-term use can lead to tolerance, meaning that higher doses are required to achieve the same effect. Narcotics are classified as controlled substances due to their potential for abuse and are subject to strict regulations.

Etorphine is a potent synthetic opioid analgesic drug that is primarily used for the immobilization and veterinary purposes in large animals. It is not commonly used in human medicine due to its high potency and potential for serious side effects, including respiratory depression and death. In medical context, etorphine is classified as a Schedule II controlled substance in the United States, due to its high abuse potential.

Etorphine works by binding to opioid receptors in the brain and spinal cord, which leads to pain relief, sedation, and decreased breathing rate. It is typically administered via injection and its effects can last for several hours. In veterinary medicine, etorphine may be used to immobilize animals such as elephants, rhinos, and large deer species for medical procedures or relocation.

It's important to note that due to its high potency and potential for serious side effects, etorphine should only be administered by trained professionals in a controlled setting.

Thiorphan is not a medical condition or disease, but rather a synthetic medication. It is a potent inhibitor of membrane-bound metalloendopeptidases, also known as neprilysin enzymes. These enzymes are responsible for breaking down certain peptides in the body, including some hormones and neurotransmitters.

Thiorphan has been used in research to study the role of these enzymes in various physiological processes. It is also being investigated as a potential therapeutic agent for conditions such as hypertension, heart failure, and Alzheimer's disease. However, it is not currently approved for clinical use in humans.

Therefore, there is no medical definition of 'Thiorphan' as a condition or disease.

Oligopeptides are defined in medicine and biochemistry as short chains of amino acids, typically containing fewer than 20 amino acid residues. These small peptides are important components in various biological processes, such as serving as signaling molecules, enzyme inhibitors, or structural elements in some proteins. They can be found naturally in foods and may also be synthesized for use in medical research and therapeutic applications.

Analgesics are a class of drugs that are used to relieve pain. They work by blocking the transmission of pain signals in the nervous system, allowing individuals to manage their pain levels more effectively. There are many different types of analgesics available, including both prescription and over-the-counter options. Some common examples include acetaminophen (Tylenol), ibuprofen (Advil or Motrin), and opioids such as morphine or oxycodone.

The choice of analgesic will depend on several factors, including the type and severity of pain being experienced, any underlying medical conditions, potential drug interactions, and individual patient preferences. It is important to use these medications as directed by a healthcare provider, as misuse or overuse can lead to serious side effects and potential addiction.

In addition to their pain-relieving properties, some analgesics may also have additional benefits such as reducing inflammation (like in the case of nonsteroidal anti-inflammatory drugs or NSAIDs) or causing sedation (as with certain opioids). However, it is essential to weigh these potential benefits against the risks and side effects associated with each medication.

When used appropriately, analgesics can significantly improve a person's quality of life by helping them manage their pain effectively and allowing them to engage in daily activities more comfortably.

Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification to become active. These modifications typically include cleavage of the precursor protein by specific enzymes, resulting in the release of the active protein. This process allows for the regulation and control of protein activity within the body. Protein precursors can be found in various biological processes, including the endocrine system where they serve as inactive hormones that can be converted into their active forms when needed.

Morphinans are a class of organic compounds that share a common skeletal structure, which is based on the morphine molecule. The morphinan structure consists of a tetracyclic ring system made up of three six-membered benzene rings (A, C, and D) fused to a five-membered dihydrofuran ring (B).

Morphinans are important in medicinal chemistry because many opioid analgesics, such as morphine, hydromorphone, oxymorphone, and levorphanol, are derived from or structurally related to morphinans. These compounds exert their pharmacological effects by binding to opioid receptors in the brain and spinal cord, which are involved in pain perception, reward, and addictive behaviors.

It is worth noting that while all opiates (drugs derived from the opium poppy) are morphinans, not all morphinans are opiates. Some synthetic or semi-synthetic morphinans, such as fentanyl and methadone, do not have a natural origin but still share the same basic structure and pharmacological properties.

Tiopronin is a medication that belongs to a class of drugs called mucolytic agents. It works by breaking down mucus in the respiratory tract, making it easier to cough up and clear the airways. Tiopronin is also known as tiopronin sodium or Thiola®.

In addition to its use as a mucolytic agent, tiopronin has been found to be effective in reducing the formation of cystine kidney stones in patients with a rare genetic disorder called cystinuria. It works by binding to cystine in the urine and preventing it from forming into crystals or stones.

Tiopronin is available as a tablet or oral solution and is typically taken several times a day, with dosing adjusted based on the patient's individual needs and response to treatment. Common side effects of tiopronin include stomach upset, loss of appetite, and rash.

Neprilysin (NEP), also known as membrane metallo-endopeptidase or CD10, is a type II transmembrane glycoprotein that functions as a zinc-dependent metalloprotease. It is widely expressed in various tissues, including the kidney, brain, heart, and vasculature. Neprilysin plays a crucial role in the breakdown and regulation of several endogenous bioactive peptides, such as natriuretic peptides, bradykinin, substance P, and angiotensin II. By degrading these peptides, neprilysin helps maintain cardiovascular homeostasis, modulate inflammation, and regulate neurotransmission. In the context of heart failure, neprilysin inhibitors have been developed to increase natriuretic peptide levels, promoting diuresis and vasodilation, ultimately improving cardiac function.

The adrenal medulla is the inner part of the adrenal gland, which is located on top of the kidneys. It is responsible for producing and releasing hormones such as epinephrine (also known as adrenaline) and norepinephrine (also known as noradrenaline). These hormones play a crucial role in the body's "fight or flight" response, preparing the body for immediate action in response to stress.

Epinephrine increases heart rate, blood pressure, and respiratory rate, while also increasing blood flow to muscles and decreasing blood flow to the skin and digestive system. Norepinephrine has similar effects but is generally less potent than epinephrine. Together, these hormones help to prepare the body for physical activity and increase alertness and focus.

Disorders of the adrenal medulla can lead to a variety of symptoms, including high blood pressure, rapid heart rate, anxiety, and tremors. Some conditions that affect the adrenal medulla include pheochromocytoma, a tumor that causes excessive production of epinephrine and norepinephrine, and neuroblastoma, a cancerous tumor that arises from immature nerve cells in the adrenal gland.

Pyrrolidines are not a medical term per se, but they are a chemical compound that can be encountered in the field of medicine and pharmacology. Pyrrolidine is an organic compound with the molecular formula (CH2)4NH. It is a cyclic secondary amine, which means it contains a nitrogen atom surrounded by four carbon atoms in a ring structure.

Pyrrolidines can be found in certain natural substances and are also synthesized for use in pharmaceuticals and research. They have been used as building blocks in the synthesis of various drugs, including some muscle relaxants, antipsychotics, and antihistamines. Additionally, pyrrolidine derivatives can be found in certain plants and fungi, where they may contribute to biological activity or toxicity.

It is important to note that while pyrrolidines themselves are not a medical condition or diagnosis, understanding their chemical properties and uses can be relevant to the study and development of medications.

Chromaffin granules are membrane-bound organelles found in the cytoplasm of chromaffin cells, which are a type of neuroendocrine cell. These cells are located in the adrenal medulla and some sympathetic ganglia and play a crucial role in the body's stress response.

Chromaffin granules contain a variety of substances, including catecholamines such as epinephrine (adrenaline) and norepinephrine (noradrenaline), as well as proteins and other molecules. When the chromaffin cell is stimulated, the granules fuse with the cell membrane and release their contents into the extracellular space, where they can bind to receptors on nearby cells and trigger a variety of physiological responses.

The name "chromaffin" comes from the fact that these granules contain enzymes that can react with chromium salts to produce a brown color, which is why they are also sometimes referred to as "black-brown granules."

The Globus Pallidus is a structure in the brain that is part of the basal ganglia, a group of nuclei associated with movement control and other functions. It has two main subdivisions: the external (GPe) and internal (GPi) segments. The GPe receives input from the striatum and sends inhibitory projections to the subthalamic nucleus, while the GPi sends inhibitory projections to the thalamus, which in turn projects to the cerebral cortex. These connections allow for the regulation of motor activity, with abnormal functioning of the Globus Pallidus being implicated in various movement disorders such as Parkinson's disease and Huntington's disease.

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.

Somatostatin is a hormone that inhibits the release of several hormones and also has a role in slowing down digestion. It is produced by the body in various parts of the body, including the hypothalamus (a part of the brain), the pancreas, and the gastrointestinal tract.

Somatostatin exists in two forms: somatostatin-14 and somatostatin-28, which differ in their length. Somatostatin-14 is the predominant form found in the brain, while somatostatin-28 is the major form found in the gastrointestinal tract.

Somatostatin has a wide range of effects on various physiological processes, including:

* Inhibiting the release of several hormones such as growth hormone, insulin, glucagon, and gastrin
* Slowing down digestion by inhibiting the release of digestive enzymes from the pancreas and reducing blood flow to the gastrointestinal tract
* Regulating neurotransmission in the brain

Somatostatin is used clinically as a diagnostic tool for detecting certain types of tumors that overproduce growth hormone or other hormones, and it is also used as a treatment for some conditions such as acromegaly (a condition characterized by excessive growth hormone production) and gastrointestinal disorders.

The ileum is the third and final segment of the small intestine, located between the jejunum and the cecum (the beginning of the large intestine). It plays a crucial role in nutrient absorption, particularly for vitamin B12 and bile salts. The ileum is characterized by its thin, lined walls and the presence of Peyer's patches, which are part of the immune system and help surveil for pathogens.

Drug tolerance is a medical concept that refers to the decreased response to a drug following its repeated use, requiring higher doses to achieve the same effect. This occurs because the body adapts to the presence of the drug, leading to changes in the function or expression of targets that the drug acts upon, such as receptors or enzymes. Tolerance can develop to various types of drugs, including opioids, benzodiazepines, and alcohol, and it is often associated with physical dependence and addiction. It's important to note that tolerance is different from resistance, which refers to the ability of a pathogen to survive or grow in the presence of a drug, such as antibiotics.

Dihydromorphine is a semi-synthetic opioid agonist that is derived from morphine, which is a natural opiate alkaloid found in the poppy plant (Papaver somniferum). It is a potent analgesic drug used to treat moderate to severe pain. Dihydromorphine works by binding to and activating the mu-opioid receptors in the brain and spinal cord, which inhibits the transmission of pain signals and produces a subjective feeling of euphoria or pleasure.

Dihydromorphine is similar in structure and effects to other opioids such as heroin, oxycodone, and hydromorphone. It has a rapid onset of action and can produce strong analgesic effects, but it also carries a high risk of dependence, addiction, and respiratory depression, which can be fatal if not treated promptly.

Dihydromorphine is available in various forms, including tablets, injectable solutions, and suppositories. It is primarily used in Europe and Asia for the treatment of pain, although it has been largely replaced by other opioids such as morphine and fentanyl in many countries due to its higher abuse potential and narrower therapeutic index.

The vas deferens is a muscular tube that carries sperm from the epididymis to the urethra during ejaculation in males. It is a part of the male reproductive system and is often targeted in surgical procedures like vasectomy, which is a form of permanent birth control.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

"Inbred strains of rats" are genetically identical rodents that have been produced through many generations of brother-sister mating. This results in a high degree of homozygosity, where the genes at any particular locus in the genome are identical in all members of the strain.

Inbred strains of rats are widely used in biomedical research because they provide a consistent and reproducible genetic background for studying various biological phenomena, including the effects of drugs, environmental factors, and genetic mutations on health and disease. Additionally, inbred strains can be used to create genetically modified models of human diseases by introducing specific mutations into their genomes.

Some commonly used inbred strains of rats include the Wistar Kyoto (WKY), Sprague-Dawley (SD), and Fischer 344 (F344) rat strains. Each strain has its own unique genetic characteristics, making them suitable for different types of research.

Substance P is an undecapeptide neurotransmitter and neuromodulator, belonging to the tachykinin family of peptides. It is widely distributed in the central and peripheral nervous systems and is primarily found in sensory neurons. Substance P plays a crucial role in pain transmission, inflammation, and various autonomic functions. It exerts its effects by binding to neurokinin 1 (NK-1) receptors, which are expressed on the surface of target cells. Apart from nociception and inflammation, Substance P is also involved in regulating emotional behaviors, smooth muscle contraction, and fluid balance.

Intraventricular injections are a type of medical procedure where medication is administered directly into the cerebral ventricles of the brain. The cerebral ventricles are fluid-filled spaces within the brain that contain cerebrospinal fluid (CSF). This procedure is typically used to deliver drugs that target conditions affecting the central nervous system, such as infections or tumors.

Intraventricular injections are usually performed using a thin, hollow needle that is inserted through a small hole drilled into the skull. The medication is then injected directly into the ventricles, allowing it to circulate throughout the CSF and reach the brain tissue more efficiently than other routes of administration.

This type of injection is typically reserved for situations where other methods of drug delivery are not effective or feasible. It carries a higher risk of complications, such as bleeding, infection, or damage to surrounding tissues, compared to other routes of administration. Therefore, it is usually performed by trained medical professionals in a controlled clinical setting.

The corpus striatum is a part of the brain that plays a crucial role in movement, learning, and cognition. It consists of two structures called the caudate nucleus and the putamen, which are surrounded by the external and internal segments of the globus pallidus. Together, these structures form the basal ganglia, a group of interconnected neurons that help regulate voluntary movement.

The corpus striatum receives input from various parts of the brain, including the cerebral cortex, thalamus, and other brainstem nuclei. It processes this information and sends output to the globus pallidus and substantia nigra, which then project to the thalamus and back to the cerebral cortex. This feedback loop helps coordinate and fine-tune movements, allowing for smooth and coordinated actions.

Damage to the corpus striatum can result in movement disorders such as Parkinson's disease, Huntington's disease, and dystonia. These conditions are characterized by abnormal involuntary movements, muscle stiffness, and difficulty initiating or controlling voluntary movements.

Benzylidene compounds are organic chemical compounds that contain a benzylidene group, which is a functional group consisting of a carbon atom double-bonded to a carbonyl group and single-bonded to a phenyl ring. The general structure of a benzylidene compound can be represented as R-CH=C(Ph)-O-, where R is an organic residue and Ph represents the phenyl group.

These compounds are known for their wide range of applications in various fields, including pharmaceuticals, agrochemicals, dyes, and perfumes. Some benzylidene compounds exhibit biological activities, such as anti-inflammatory, antimicrobial, and anticancer properties, making them valuable candidates for drug development.

It is important to note that the term 'benzylidene' refers only to the functional group and not to a specific class of compounds. Therefore, there are many different types of benzylidene compounds with varying chemical structures and properties.

Spinal injections, also known as epidural injections or intrathecal injections, are medical procedures involving the injection of medications directly into the spinal canal. The medication is usually delivered into the space surrounding the spinal cord (the epidural space) or into the cerebrospinal fluid that surrounds and protects the spinal cord (the subarachnoid space).

The medications used in spinal injections can include local anesthetics, steroids, opioids, or a combination of these. The purpose of spinal injections is to provide diagnostic information, therapeutic relief, or both. They are commonly used to treat various conditions affecting the spine, such as radicular pain (pain that radiates down the arms or legs), disc herniation, spinal stenosis, and degenerative disc disease.

Spinal injections can be administered using different techniques, including fluoroscopy-guided injections, computed tomography (CT) scan-guided injections, or with the help of a nerve stimulator. These techniques ensure accurate placement of the medication and minimize the risk of complications.

It is essential to consult a healthcare professional for specific information regarding spinal injections and their potential benefits and risks.

Carboxypeptidases are a group of enzymes that catalyze the cleavage of peptide bonds at the carboxyl-terminal end of polypeptides or proteins. They specifically remove the last amino acid residue from the protein chain, provided that it has a free carboxyl group and is not blocked by another chemical group. Carboxypeptidases are classified into two main types based on their catalytic mechanism: serine carboxypeptidases and metallo-carboxypeptidases.

Serine carboxypeptidases, also known as chymotrypsin C or carboxypeptidase C, use a serine residue in their active site to catalyze the hydrolysis of peptide bonds. They are found in various organisms, including animals and bacteria.

Metallo-carboxypeptidases, on the other hand, require a metal ion (usually zinc) for their catalytic activity. They can be further divided into several subtypes based on their structure and substrate specificity. For example, carboxypeptidase A prefers to cleave hydrophobic amino acids from the carboxyl-terminal end of proteins, while carboxypeptidase B specifically removes basic residues (lysine or arginine).

Carboxypeptidases have important roles in various biological processes, such as protein maturation, digestion, and regulation of blood pressure. Dysregulation of these enzymes has been implicated in several diseases, including cancer, neurodegenerative disorders, and cardiovascular disease.

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.

The myenteric plexus, also known as Auerbach's plexus, is a component of the enteric nervous system located in the wall of the gastrointestinal tract. It is a network of nerve cells (neurons) and supporting cells (neuroglia) that lies between the inner circular layer and outer longitudinal muscle layers of the digestive system's muscularis externa.

The myenteric plexus plays a crucial role in controlling gastrointestinal motility, secretion, and blood flow, primarily through its intrinsic nerve circuits called reflex arcs. These reflex arcs regulate peristalsis (the coordinated muscle contractions that move food through the digestive tract) and segmentation (localized contractions that mix and churn the contents within a specific region of the gut).

Additionally, the myenteric plexus receives input from both the sympathetic and parasympathetic divisions of the autonomic nervous system, allowing for central nervous system regulation of gastrointestinal functions. Dysfunction in the myenteric plexus has been implicated in various gastrointestinal disorders, such as irritable bowel syndrome, achalasia, and intestinal pseudo-obstruction.

The locus coeruleus (LC) is a small nucleus in the brainstem, specifically located in the rostral pons and dorsal to the fourth ventricle. It is the primary site of noradrenaline (norepinephrine) synthesis, storage, and release in the central nervous system. The LC projects its neuronal fibers widely throughout the brain, including the cerebral cortex, thalamus, hippocampus, amygdala, and spinal cord. It plays a crucial role in various physiological functions such as arousal, attention, learning, memory, stress response, and regulation of the sleep-wake cycle. The LC's activity is associated with several neurological and psychiatric conditions, including anxiety disorders, depression, post-traumatic stress disorder (PTSD), and neurodegenerative diseases like Parkinson's and Alzheimer's disease.

Morphine derivatives are substances that are synthesized from or structurally similar to morphine, a natural opiate alkaloid found in the opium poppy. These compounds share many of the same pharmacological properties as morphine and are often used for their analgesic (pain-relieving), sedative, and anxiolytic (anxiety-reducing) effects.

Examples of morphine derivatives include:

1. Hydrocodone: A semi-synthetic opioid that is often combined with acetaminophen for the treatment of moderate to severe pain.
2. Oxycodone: A synthetic opioid that is used for the management of moderate to severe pain, either alone or in combination with other medications.
3. Hydromorphone: A potent semi-synthetic opioid that is used for the treatment of severe pain, typically in a hospital setting.
4. Oxymorphone: A synthetic opioid that is similar to hydromorphone in its potency and use for managing severe pain.
5. Codeine: A naturally occurring opiate alkaloid that is less potent than morphine but still has analgesic, cough suppressant, and antidiarrheal properties. It is often combined with other medications for various therapeutic purposes.
6. Fentanyl: A synthetic opioid that is significantly more potent than morphine and is used for the management of severe pain, typically in a hospital or clinical setting.

It's important to note that while these derivatives can be beneficial for managing pain and other symptoms, they also carry a risk of dependence, addiction, and potentially life-threatening side effects such as respiratory depression. As a result, their use should be closely monitored by healthcare professionals and prescribed cautiously.

Neurotransmitter agents are substances that affect the synthesis, storage, release, uptake, degradation, or reuptake of neurotransmitters, which are chemical messengers that transmit signals across a chemical synapse from one neuron to another. These agents can be either agonists, which mimic the action of a neurotransmitter and bind to its receptor, or antagonists, which block the action of a neurotransmitter by binding to its receptor without activating it. They are used in medicine to treat various neurological and psychiatric disorders, such as depression, anxiety, and Parkinson's disease.

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.

"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.

Neuroblastoma is defined as a type of cancer that develops from immature nerve cells found in the fetal or early postnatal period, called neuroblasts. It typically occurs in infants and young children, with around 90% of cases diagnosed before age five. The tumors often originate in the adrenal glands but can also arise in the neck, chest, abdomen, or spine. Neuroblastoma is characterized by its ability to spread (metastasize) to other parts of the body, including bones, bone marrow, lymph nodes, and skin. The severity and prognosis of neuroblastoma can vary widely, depending on factors such as the patient's age at diagnosis, stage of the disease, and specific genetic features of the tumor.

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.

Protease inhibitors are a class of antiviral drugs that are used to treat infections caused by retroviruses, such as the human immunodeficiency virus (HIV), which is responsible for causing AIDS. These drugs work by blocking the activity of protease enzymes, which are necessary for the replication and multiplication of the virus within infected cells.

Protease enzymes play a crucial role in the life cycle of retroviruses by cleaving viral polyproteins into functional units that are required for the assembly of new viral particles. By inhibiting the activity of these enzymes, protease inhibitors prevent the virus from replicating and spreading to other cells, thereby slowing down the progression of the infection.

Protease inhibitors are often used in combination with other antiretroviral drugs as part of highly active antiretroviral therapy (HAART) for the treatment of HIV/AIDS. Common examples of protease inhibitors include saquinavir, ritonavir, indinavir, and atazanavir. While these drugs have been successful in improving the outcomes of people living with HIV/AIDS, they can also cause side effects such as nausea, diarrhea, headaches, and lipodystrophy (changes in body fat distribution).

The chromaffin system is a part of the autonomic nervous system that consists of specialized cells called chromaffin cells. These cells are found in two main locations: the adrenal medulla, which is the inner portion of the adrenal glands located on top of the kidneys; and scattered throughout various nerve ganglia along the sympathetic trunk, a chain of ganglia that runs parallel to the spinal cord.

Chromaffin cells are responsible for synthesizing, storing, and releasing catecholamines, which are hormones and neurotransmitters that help regulate various bodily functions such as heart rate, blood pressure, and metabolism. The most well-known catecholamines are adrenaline (epinephrine) and noradrenaline (norepinephrine), which are released in response to stress or excitement.

The term "chromaffin" refers to the ability of these cells to take up chromium salts and produce a brown coloration, which is why they are called chromaffin cells. The chromaffin system plays an important role in the body's fight-or-flight response, helping to prepare the body for immediate action in response to perceived threats or stressors.

Nociceptive pain is a type of pain that results from the activation of nociceptors, which are specialized sensory receptors located in various tissues throughout the body. These receptors detect potentially harmful stimuli such as extreme temperatures, pressure, or chemical irritants and transmit signals to the brain, which interprets them as painful sensations.

Nociceptive pain can be further classified into two categories:

1. Somatic nociceptive pain: This type of pain arises from the activation of nociceptors in the skin, muscles, bones, and joints. It is often described as sharp, aching, or throbbing and may be localized to a specific area of the body.
2. Visceral nociceptive pain: This type of pain arises from the activation of nociceptors in the internal organs, such as the lungs, heart, and digestive system. It is often described as deep, cramping, or aching and may be more diffuse and difficult to localize.

Examples of conditions that can cause nociceptive pain include injuries, arthritis, cancer, and infections. Effective management of nociceptive pain typically involves a multimodal approach that includes pharmacologic interventions, such as non-opioid analgesics, opioids, and adjuvant medications, as well as non-pharmacologic therapies, such as physical therapy, acupuncture, and cognitive-behavioral therapy.

The spinal cord is a major part of the nervous system, extending from the brainstem and continuing down to the lower back. It is a slender, tubular bundle of nerve fibers (axons) and support cells (glial cells) that carries signals between the brain and the rest of the body. The spinal cord primarily serves as a conduit for motor information, which travels from the brain to the muscles, and sensory information, which travels from the body to the brain. It also contains neurons that can independently process and respond to information within the spinal cord without direct input from the brain.

The spinal cord is protected by the bony vertebral column (spine) and is divided into 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Each segment corresponds to a specific region of the body and gives rise to pairs of spinal nerves that exit through the intervertebral foramina at each level.

The spinal cord is responsible for several vital functions, including:

1. Reflexes: Simple reflex actions, such as the withdrawal reflex when touching a hot surface, are mediated by the spinal cord without involving the brain.
2. Muscle control: The spinal cord carries motor signals from the brain to the muscles, enabling voluntary movement and muscle tone regulation.
3. Sensory perception: The spinal cord transmits sensory information, such as touch, temperature, pain, and vibration, from the body to the brain for processing and awareness.
4. Autonomic functions: The sympathetic and parasympathetic divisions of the autonomic nervous system originate in the thoracolumbar and sacral regions of the spinal cord, respectively, controlling involuntary physiological responses like heart rate, blood pressure, digestion, and respiration.

Damage to the spinal cord can result in various degrees of paralysis or loss of sensation below the level of injury, depending on the severity and location of the damage.

Galanin is a neuropeptide, which is a type of small protein molecule that functions as a neurotransmitter or neuromodulator in the nervous system. It is widely distributed throughout the central and peripheral nervous systems of vertebrates and plays important roles in various physiological functions, including modulation of pain perception, regulation of feeding behavior, control of circadian rhythms, and cognitive processes such as learning and memory.

Galanin is synthesized from a larger precursor protein called preprogalanin, which is cleaved into several smaller peptides, including galanin itself, galanin message-associated peptide (GMAP), and alarin. Galanin exerts its effects by binding to specific G protein-coupled receptors, known as the galanin receptor family, which includes three subtypes: GalR1, GalR2, and GalR3. These receptors are widely expressed in various tissues and organs, including the brain, spinal cord, gastrointestinal tract, pancreas, and cardiovascular system.

Galanin has been implicated in several pathological conditions, such as chronic pain, depression, anxiety, epilepsy, and neurodegenerative disorders like Alzheimer's disease and Parkinson's disease. As a result, there is ongoing research into the development of galanin-based therapies for these conditions.

Substantia gelatinosa (SG) is a term used in anatomy to refer to a part of the gray matter in the dorsal horn of the spinal cord. It's located in the most posterior and lateral portion of the dorsal horn, and it is characterized by its gelatinous appearance due to the high content of neuroglial cells and neuropil.

The substantia gelatinosa plays a crucial role in sensory processing, particularly in pain perception. It contains a variety of neurons that receive input from primary afferent fibers (both myelinated Aδ and unmyelinated C fibers) carrying nociceptive information from the periphery. The SG also contains interneurons that modulate the transmission of these nociceptive signals to higher brain centers, thus contributing to the complex processing of pain.

Furthermore, the substantia gelatinosa is involved in the regulation of autonomic functions and temperature sensation. It's worth noting that the term "substantia gelatinosa" is sometimes used interchangeably with "lamina II," as they refer to the same anatomical structure. However, some sources prefer to differentiate between them by using "substantia gelatinosa" for the entire region and "lamina II" specifically for the cellular layer of this region.

Electric stimulation, also known as electrical nerve stimulation or neuromuscular electrical stimulation, is a therapeutic treatment that uses low-voltage electrical currents to stimulate nerves and muscles. It is often used to help manage pain, promote healing, and improve muscle strength and mobility. The electrical impulses can be delivered through electrodes placed on the skin or directly implanted into the body.

In a medical context, electric stimulation may be used for various purposes such as:

1. Pain management: Electric stimulation can help to block pain signals from reaching the brain and promote the release of endorphins, which are natural painkillers produced by the body.
2. Muscle rehabilitation: Electric stimulation can help to strengthen muscles that have become weak due to injury, illness, or surgery. It can also help to prevent muscle atrophy and improve range of motion.
3. Wound healing: Electric stimulation can promote tissue growth and help to speed up the healing process in wounds, ulcers, and other types of injuries.
4. Urinary incontinence: Electric stimulation can be used to strengthen the muscles that control urination and reduce symptoms of urinary incontinence.
5. Migraine prevention: Electric stimulation can be used as a preventive treatment for migraines by applying electrical impulses to specific nerves in the head and neck.

It is important to note that electric stimulation should only be administered under the guidance of a qualified healthcare professional, as improper use can cause harm or discomfort.

The met-enkephalin peptide sequence is coded for by the enkephalin gene; the leu-enkephalin peptide sequence is coded for by ... Met-enkephalin is Tyr-Gly-Gly-Phe-Met. Leu-enkephalin has Tyr-Gly-Gly-Phe-Leu. There are three well-characterized families of ... An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. The enkephalins are termed ... but the endorphin peptide is not processed into enkephalin. Enkephalin is also considered a neuropeptide, which in the human ...
It is one of the two forms of enkephalin, the other being leu-enkephalin. The enkephalins are considered to be the primary ... Benuck M, Berg MJ, Marks N (1982). "Separate metabolic pathways for Leu-enkephalin and Met-enkephalin-Arg(6)-Phe(7) degradation ... the heptapeptide met-enkephalin-arg-phe (261-267), and the octapeptide met-enkephalin-arg-gly-leu (186-193), though whether ... hence why met-enkephalin is sometimes called OGF instead. Met-enkephalin has low bioavailability, is rapidly metabolized, and ...
It is one of the two forms of enkephalin; the other is met-enkephalin. The tyrosine residue at position 1 is thought to be ... Hughes J, Kosterlitz HW, Smith TW (February 1997). "The distribution of methionine-enkephalin and leucine-enkephalin in the ... Leu-enkephalin is an endogenous opioid peptide neurotransmitter with the amino acid sequence Tyr-Gly-Gly-Phe-Leu that is found ... Met-enkephalin Colaianni L, Kung SC, Taggart DK, Picca RA, Greaves J, Penner RM, Cioffi N (July 2014). "Reduction of spectral ...
"Opiate receptors and enkephalins". Lasker Foundation. Retrieved 8 January 2017. Goldberg, Jeff (2013). Anatomy of a Scientific ... While working with Kosterlitz at Aberdeen, Hughes helped discover the enkephalin peptides. Kosterlitz had developed assays for ... who shared the 1978 Albert Lasker Award for Basic Medical Research for the discovery of met-enkephalin and leu-enkephalin. This ... and leu-enkephalin, as naturally occurring molecules from the brain, that have activity resembling opioids. Hughes and ...
Oka T, Hiranuma T, Liu XF, Ohgiya N, Iwao K, Matsumiya T (1993). "[Enkephalin-inactivating enzymes]". Nippon Yakurigaku Zasshi ... It also inhibits the degradation of met-enkephalin, dynorphin A, and other endogenous peptides. Bestatin Pepstatin John ...
e.g., enkephalin). A hexapeptide has six amino acids. (e.g., angiotensin IV). A heptapeptide has seven amino acids. (e.g., ... peptides Enkephalin pentapeptides Prodynorphin peptides Calcitonin Amylin AGG01 Aromatic short peptides Biomimetic peptides ...
They include endorphins, enkephalins, dynorphins and endomorphins. These peptides are especially important for modulating pain ...
Endogenous opiates include endorphins, enkephalins, dynorphins, and endomorphins. Transcription and translation of opiate- ...
The human gene for dynorphins (originally called the "Enkephalin B" gene because of sequence similarity to the enkephalin gene ... Principal endogenous agonists (Human) β-endorphin (POMC, P01189), [Leu]enkephalin (PENK, P01210), [Met]enkephalin (PENK, P01210 ... enkephalin (PENK, P01210), [Leu]enkephalin (PENK, P01210) {{cite web}}: External link in ,quote= (help) Li Y, Lefever MR, Muthu ... Opiorphin and spinorphin, enkephalinase inhibitors (i.e., prevent the metabolism of enkephalins). Hemorphins, hemoglobin- ...
They isolated "enkephalins" (from the Greek εγκέφαλος, cerebrum) from pig brain, identified as Met-enkephalin and Leu- ... The endorphins are all synthesized from the precursor protein, proopiomelanocortin, and all contain a Met-enkephalin motif at ... Studies have subsequently distinguished between enkephalins, endorphins, and endogenously produced morphine, which is not a ... enkephalin. This came after the discovery of a receptor that was proposed to produce the pain-relieving analgesic effects of ...
Principal endogenous agonists (Human) β-endorphin (POMC, P01189), [Met]enkephalin (PENK, P01210), [Leu]enkephalin (PENK, P01210 ... from which met-enkephalin and leu-enkephalin are derived; and prodynorphin, which is the precursor of dynorphin and related ... Although they vary in length from as few as five amino acids (enkephalins) to as many as 31 (β-endorphin), the endogenous ... They noticed that the C-terminus region of this neuropeptide was similar to that of some enkephalins, suggesting that it may ...
Similarity to carboxypeptidase H (enkephalin convertase)". The Biochemical Journal. 261 (1): 289-91. PMC 1138816. PMID 2775217 ...
Met]Enkephalin Frakefamide J S Davies; Royal Soc of Chem (8 November 2000). Amino Acids, Peptides and Proteins. Royal Society ... As an example, while its parent peptide, [Met]enkephalin, has an in vivo half-life of merely seconds, metkefamide has a half- ... enkephalin with the amino acid sequence Tyr-D-Ala-Gly-Phe-(N-Me)-Met-NH2. It behaves as a potent agonist of the δ- and μ-opioid ... a systemically active analog of methionine enkephalin with potent opioid alpha-receptor activity". Science. 211 (4482): 603-5. ...
205-207 Waterfield AA, Smockcum RWJ... Henderson G (1977). In vitro pharmacology of the opioid peptides, enkephalins, and ...
... and so RB-101 causes a buildup of both Met-enkephalin and Leu-enkephalin. These peptides act primarily at the delta opioid ... Noble F, Soleilhac JM, Soroca-Lucas E, Turcaud S, Fournie-Zaluski MC, Roques BP (April 1992). "Inhibition of the enkephalin- ... Roques BP, Noble F (November 1996). "Association of enkephalin catabolism inhibitors and CCK-B antagonists: a potential use in ... This inhibits the breakdown of the endogenous opioid peptides known as enkephalins. These two enzymes, aminopeptidase N (APN) ...
CPA6 is also one of several enzymes which degrade enkephalins. CPA-1 and CPA-2 (and, it is presumed, all other CPAs) employ a ...
July 2003). "Pain management by a new series of dual inhibitors of enkephalin degrading enzymes: long lasting antinociceptive ... an inhibitor of enkephalin catabolism, and the CCKB antagonist PD-134,308". British Journal of Pharmacology. 114 (5): 1031-9. ... "CCK-B antagonists exhibit antidepressant-like effects and potentiate endogenous enkephalin analgesia. Correlation with in vivo ... "Cholecystokinin B antagonists strongly potentiate antinociception mediated by endogenous enkephalins". The Journal of ...
Activation of this receptor produces strong analgesia and release of met-enkephalin; a number of widely used opioid agonists, ... The endogenous opioids are dynorphins, enkephalins, endorphins, endomorphins and nociceptin. The opioid receptors are ~40% ... which has been shown to be a cellular growth factor modulator with met-enkephalin being the endogenous ligand. This receptor is ...
The endogenous opioids are dynorphins, enkephalins, endorphins, endomorphins, and nociceptin. The opioid receptors are ~40% ...
... is a dimeric enkephalin endogenous peptide (Tyr-D-Ala-Gly-Phe-NH)2 composed of two tetrapeptides derived from ... June 1993). "Antinociceptive profile of biphalin, a dimeric enkephalin analog". The Journal of Pharmacology and Experimental ... enkephalins, connected 'tail-to-tail' by a hydrazide bridge. The presence of two distinct pharmacophores confers on biphalin a ...
It has enkephalin-producing cells that suppress pain. The periaqueductal gray is the gray matter located around the cerebral ... Stimulation of the periaqueductal gray matter of the midbrain activates enkephalin-releasing neurons that project to the raphe ... these interneurons release either enkephalin or dynorphin (endogenous opioid neurotransmitters), which bind to mu and kappa ...
Benuck M, Berg MJ, Marks N (1982). "Separate metabolic pathways for Leu-enkephalin and Met-enkephalin-Arg(6)-Phe(7) degradation ... Notably, inhibition of ACE also reduces enkephalin catabolism. Casomorphin Brantl V, Gramsch C, Lottspeich F, Mertz R, Jaeger ...
It releases GABA, enkephalin, substance P, and acetylcholine. It receives serotonin and glutamate. The putamen is ... It employs GABA, acetylcholine, and enkephalin to perform its functions. The putamen also plays a role in degenerative ...
... "beta-Lipotropin as a prohormone for the morphinomimetic peptides endorphins and enkephalins". Proceedings of the National ...
Mosnaim reported plasma levels of the endogenous opioid pentapeptide methionine-enkephalin in various patient populations, and ... "Plasma Methionine Enkephalin Levels - A Biological Marker for Migraine?". Headache: The Journal of Head and Face Pain. 25 (5): ... "In vitro Human Plasma Leucine5-Enkephalin Degradation Is Inhibited by a Select Number of Drugs with the Phenothiazine Molecule ... enkephalins, α-interferon, interleukin-2, taxol, and lipopolysaccharide. Noncatecholic phenylethylamines Part 1 (1978) ISBN 0- ...
Benuck M, Berg MJ, Marks N (1982). "Separate metabolic pathways for Leu-enkephalin and Met-enkephalin-Arg(6)-Phe(7) degradation ... Enkephalinases are enzymes that degrade endogenous enkephalin opioid peptides. They include: Aminopeptidase N (APN) Neutral ...
... produces the enkephalin peptides [Met]enkephalin, and to a lesser extent, [Leu]enkephalin. Upon cleavage, each proenkephalin ... enkephalin, and one copy of [Leu]enkephalin. Contrarily, [Leu]enkephalin] is predominantly synthesized from prodynorphin, which ... Pro-Enkephalin at the U.S. National Library of Medicine Medical Subject Headings (MeSH) (Articles with short description, Short ... Boarder MR, Evans C, Adams M, Erdelyi E, Barchas JD (December 1987). "Peptide E and its products, BAM 18 and Leu-enkephalin, in ...
... ([D-Pen2,D-Pen5]enkephalin) is a synthetic opioid peptide and a selective agonist of the δ-opioid receptor (DOR) which is ... It was derived from structural modification of met-enkephalin. DADLE DAMGO Tseong LF (1 September 1995). Pharmacology of Opioid ...
Enkephalins come in two forms, met-enkephalin and leu-enkephalin, which are involved in regulating nociception in the ... Enkephalin-like peptides have been found in neurones of the palliovisceral lobe of the brain in the common octopus, and met- ... Leu-enkephalin and delta receptors have been found in the mantle, arms and other tissues in Amphioctopus fangsiao. Naloxone is ... Sha, A., Sun, H. and Wang, Y. (2012). "Immunohistochemical study of leucine-enkephalin and delta opioid receptor in mantles and ...
These drugs mimic three classes of endorphins, such as endomorphins, enkephalins, and dynorphins. All three of these classes ...
The met-enkephalin peptide sequence is coded for by the enkephalin gene; the leu-enkephalin peptide sequence is coded for by ... Met-enkephalin is Tyr-Gly-Gly-Phe-Met. Leu-enkephalin has Tyr-Gly-Gly-Phe-Leu. There are three well-characterized families of ... An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. The enkephalins are termed ... but the endorphin peptide is not processed into enkephalin. Enkephalin is also considered a neuropeptide, which in the human ...
The Entry of [d-Penicillamine2,5]Enkephalin into the Central Nervous System: Saturation Kinetics and Specificity Sarah A. ... The Entry of [d-Penicillamine2,5]Enkephalin into the Central Nervous System: Saturation Kinetics and Specificity Sarah A. ... The Entry of [d-Penicillamine2,5]Enkephalin into the Central Nervous System: Saturation Kinetics and Specificity Sarah A. ... The Entry of [d-Penicillamine2,5]Enkephalin into the Central Nervous System: Saturation Kinetics and Specificity ...
Pioro, Erik P.J. ; Trevor Hughes, J. ; Claudio Cuello, A. / Loss of substance P and Enkephalin immunoreactivity in the human ... keywords = "enkephalin, striato-pallidal infarction, substance P, substantia nigra",. author = "Pioro, {Erik P.J.} and {Trevor ... Pioro, E. P. J., Trevor Hughes, J., & Claudio Cuello, A. (1984). Loss of substance P and Enkephalin immunoreactivity in the ... Pioro EPJ, Trevor Hughes J, Claudio Cuello A. Loss of substance P and Enkephalin immunoreactivity in the human substantia nigra ...
Met-Enkephalin-Arg6-Gly7-Leu8 Antiserum Anti Met-Enkephalin-Arg6-Gly7-Leu8 Serum Host Animal: RabbitY140 50 µl , 455.00 EUR ... Met-Enkephalin-Arg6-Gly7-Leu8 Antiserum Anti Met-Enkephalin-Arg6-Gly7-Leu8 Serum Host Animal: Rabbit ... Met-Enkephalin-Arg. 455,00 €. excl. 19% VAT. .single_add_to_cart_button { display: none !important; } SKU: Y140 Category: ... Synthetic Met-Enkephalin-Arg6-Gly7-Leu8 -Ascaris suilla protein. ... Met-Enkephalin-Arg6-Gly7-Leu8 100%. Phe4-Met5-Arg6-Gly7-Leu8 , ...
Enkephalin, a naturally occurring opioid-like substance, has the potential to be a very potent painkiller. Find out more ,, ... What is Enkephalin?. One such substance is a peptide called enkephalin, a naturally occurring opioid-like substance that is ... Enkephalin and nanoparticles. Researchers in France have been successful in coating enkephalin in nanoparticles, likened to a ... This coating makes it far easier for enkephalin to cross the blood-brain barrier to locate its corresponding receptor system. ...
Hogue-Angeletti, Ruth ; Roda, L. G. / In vitro interaction of enkephalin with serum and chromaffin granule components. In: ... In vitro interaction of enkephalin with serum and chromaffin granule components. / Hogue-Angeletti, Ruth; Roda, L. G. In: ... Hogue-Angeletti, R., & Roda, L. G. (1980). In vitro interaction of enkephalin with serum and chromaffin granule components. ... Hogue-Angeletti, R & Roda, LG 1980, In vitro interaction of enkephalin with serum and chromaffin granule components, ...
Met-Enkephalin: Tyr-Gly-Gly-Phe-Met, 574.66 m/z. Method Conditions. Column: Cogent Diamond Hydride™, 4μm, 100Å. Catalog No.: ... Methionine-Enkephalin Analyzed with LCMS - AppNote. KB Home/ARTICLES, APPNOTES, FAQ / AppNotes Library / AppNotes ANP/HILIC ... No 235 Methionine-Enkephalin Analyzed with LCMS pdf 0.2 Mb Download File ... In this AppNote, the developed Method was used to analyze Methionine-Enkephalin (MEK), the resulting Peak shape was Symmetrical ...
AnaSpec manufactures many categories of peptides in Fremont, California, USA. Peptides represent over decades of innovative peptide synthesis expertise.
The POMC gene provides instructions for making a protein called proopiomelanocortin (POMC), which is cut (cleaved) into smaller pieces called peptides that have different functions in the body. Learn about this gene and related health conditions.
Inhibition of enkephalin-degrading enzymes from rat brain and of thermolysin by amino acid hydroxamates ... Enkephalin degrading enzymes are present in the electric organ of Torpedo californica ... Effect of metal chelating peptide derivatives on the enzymatic degradation of enkephalin [abstract] ... The effect of several antibiotics on the biological activity of enkephalin [abstract] ...
On-line coupling of SEC and RP-LC for the determination of structurally related enkephalins in cerebrospinal fluid. Journal of ... On-line coupling of SEC and RP-LC for the determination of structurally related enkephalins in cerebrospinal fluid. In: Journal ... Dive into the research topics of On-line coupling of SEC and RP-LC for the determination of structurally related enkephalins ... On-line coupling of SEC and RP-LC for the determination of structurally related enkephalins in cerebrospinal fluid. / Stroink, ...
In contrast, enkephalin forms similar to Met‐enkephalin‐Arg‐Phe, or Met‐enkephalin‐Arg‐Gly‐Leu, as well as mammalian α‐ ... enkephalin‐immunoreactive neurons. The distribution of Met‐enkephalin‐ and Leu‐enkephalin‐immunoreactive cell bodies and fibers ... The presence of Met‐enkephalin‐ and Leu‐enkephalin‐like peptides in distinct regions, together with the absence of dynorphin‐ ... The results show that both Met‐enkephalin‐ and Leu‐enkephalin‐immunoreactive peptides are present in the lungfish brain. ...
Singh, J., Djali, P. K., & Adeghate, E. (1998). Immunohistochemistry and secretory effects of leucine enkephalin in the ... Singh, J, Djali, PK & Adeghate, E 1998, Immunohistochemistry and secretory effects of leucine enkephalin in the isolated pig ... Immunohistochemistry and secretory effects of leucine enkephalin in the isolated pig lacrimal gland. Advances in experimental ... Immunohistochemistry and secretory effects of leucine enkephalin in the isolated pig lacrimal gland. In: Advances in ...
Met5-enkephalin (ME)-induced cardioprotection occurs via epidermal growth factor receptor (EGFR) transactivation. Met5- ... enkephalin (ME)-induced cardioprotection occurs via epidermal growth factor receptor (EGFR) transactivation with the subsequent ...
Effect of low- and high-frequency TENS on Met-enkephalin-Arg-Phe and dynorphin A immunoreactivity in human lumbar CSF. Pain. ... Studies show marked increases in beta endorphin and met-enkephalin with low-frequency TENS, with demonstrated reversal of the ... Increased beta-endorphin but not met-enkephalin levels in human cerebrospinal fluid after acupuncture for recurrent pain. ... Acupuncture relief of chronic pain syndrome correlates with increased plasma met-enkephalin concentrations. Lancet. 1983 Dec 17 ...
However, the role of leucine-enkephalin (L-ENK) in the ovarian recrudescence activity of reptiles is not known. In the present ... The enkephalins are known to regulate many physiological functions, including reproduction in vertebrates. ... Follicle stimulating hormone; Gecko; Gonadotropin-releasing hormone; Leucine-enkephalin; Opioid peptide; Ovary ... The opioid peptide leucine-enkephalin disrupts seasonal and gonadotropin-induced ovarian recrudescence in the gecko ...
2A), suggesting that when Im neurons release enkephalins, neprilysin is well positioned to cleave this enkephalin near its ... an enkephalin-degrading peptidase that cleaves the glycine-phenylalanine bond of enkephalin molecules (Hiranuma and Oka, 1986; ... 2008) Enkephalin co-expression with classic neurotransmitters in the amygdaloid complex of the rat. J Comp Neurol 506:943-959. ... Picrotoxin, methionine-enkephalin (met-enk) and captopril were from Sigma. CTAP, [D-Ala2]-Deltorphin II (Delt II), ICI-174864, ...
Dive into the research topics of INTRAMOLECULAR DONOR‐ACCEPTOR SEPARATIONS IN METHIONINE‐ AND LEUCINE‐ENKEPHALIN ESTIMATED BY ... INTRAMOLECULAR DONOR‐ACCEPTOR SEPARATIONS IN METHIONINE‐ AND LEUCINE‐ENKEPHALIN ESTIMATED BY LONG‐RANGE RADIATIONLESS TRANSFER ...
Conformational determinants of agonist versus antagonist properties of [D-Pen2,D-Pen5]enkephalin (DPDPE) analogs at opioid ... enkephalin (DPDPE) analogs at opioid receptors. Comparison of X-ray crystallographic structure, solution 1H NMR data, and ...
Stevens, C. W. ; Yaksh, T. L. / Studies of morphine and D-ala2-D-leu5-enkephalin (DADLE) cross-tolerance after continuous ... Stevens, C. W., & Yaksh, T. L. (1992). Studies of morphine and D-ala2-D-leu5-enkephalin (DADLE) cross-tolerance after ... Studies of morphine and D-ala2-D-leu5-enkephalin (DADLE) cross-tolerance after continuous intrathecal infusion in the rat. / ... Studies of morphine and D-ala2-D-leu5-enkephalin (DADLE) cross-tolerance after continuous intrathecal infusion in the rat. ...
Met-Enkephalin in Oxidative Stress. Chronic Stress Induces Death of Lymphocytes. Interleukin- and the Hypothalamic-Pituitary- ...
Enkephalins * Ligands * Peptides * Protein Precursors * Receptors, Corticotropin-Releasing Hormone * Receptors, G-Protein- ...
1) Opiods, such as beta endorphins, dynorphins, and enkephalins. Term. __________ __________ are not packaged in vesicles and ...
Running high: Enkephalin indicated. Journal of Drug Issues 10:341-349.. Peele, S. 1980. Addiction to an experience: A social- ...
Levels of acetylcholine, substance P, and enkephalins are also reduced. Nuclear magnetic resonance spectroscopy in living ...
The opioid growth factor (OGF; [Met(5)]-enkephalin) and the OGF receptor (OGFr) form an endogenous growth-regulating pathway … ... The opioid growth factor (OGF; [Met(5)]-enkephalin) and the OGF receptor (OGFr) form an endogenous growth-regulating pathway in ...
The endogenous endorphins are dynorphins, endorphins, and enkephalins. These receptors, which exist in a variety of areas in ...
Growth Hormone Deficiency in Children - Learn about the causes, symptoms, diagnosis & treatment from the Merck Manuals - Medical Consumer Version.
Theoretical studies of the amide I vibrational frequencies of [Leu]-enkephalin Molecular Physics. VOL 103(NUMB 11/12), 1531- ... Vibrational analysis of capped [Leu]enkephalin Physical Chemistry Chemical Physics. 6(10), 2580-2587 ...
  • The enkephalins are termed endogenous ligands, as they are internally derived and bind to the body's opioid receptors. (wikipedia.org)
  • The receptors for enkephalin are the delta opioid receptors and mu opioid receptors. (wikipedia.org)
  • enkephalin (DPDPE) analogs at opioid receptors. (arizona.edu)
  • Conformational determinants of agonist versus antagonist properties of [D-Pen 2 ,D-Pen 5 ]enkephalin (DPDPE) analogs at opioid receptors. (arizona.edu)
  • Dive into the research topics of 'Conformational determinants of agonist versus antagonist properties of [D-Pen 2 ,D-Pen 5 ]enkephalin (DPDPE) analogs at opioid receptors. (arizona.edu)
  • Enkephalin is the ligand for delta receptors and has no significant analgesic effect. (uspharmacist.com)
  • Delta opioid receptors bind endorphins and enkephalins with approximately equal affinity and have less affinity for dynorphins. (harvard.edu)
  • A Caged Enkephalin Optimized for Simultaneously Probing Mu and Delta Opioid Receptors. (harvard.edu)
  • Singh, J, Djali, PK & Adeghate, E 1998, ' Immunohistochemistry and secretory effects of leucine enkephalin in the isolated pig lacrimal gland ', Advances in experimental medicine and biology , vol. 438, pp. 157-161. (uaeu.ac.ae)
  • The opioid peptide leucine-enkephalin disrupts seasonal and gonadotropin-induced ovarian recrudescence in the gecko Hemidactylus frenatus. (bvsalud.org)
  • However, the role of leucine - enkephalin (L-ENK) in the ovarian recrudescence activity of reptiles is not known. (bvsalud.org)
  • Another theory is called The Endorphin Release, which suggests that electrical impulses stimulate the production of endorphins and encephalin in the body. (selfgrowth.com)
  • Met(5)]-enkephalin) and the OGF receptor (OGFr) form an endogenous growth-regulating pathway in homeostasis and neoplasia. (nih.gov)
  • Stable Peptide of the Endogenous Opioid Enkephalin Precursor and Breast Cancer Risk. (lu.se)
  • Enkephalin is also considered a neuropeptide, which in the human body performs as an important signaling molecule in the brain. (wikipedia.org)
  • Enkephalins are found in high concentration in the brain as well as in the cells of adrenal medulla. (wikipedia.org)
  • This coating makes it far easier for enkephalin to cross the blood-brain barrier to locate its corresponding receptor system. (blbchronicpain.co.uk)
  • As the enkephalins are widely distributed neurotransmitters and neurohormones found in the brain, spinal cord, pituitary, adrenal medulla, autonomic nervous system, and gastrointestinal tract, changes in their concentration may influence many functions. (cdc.gov)
  • Produces coordinates from the met-enkephalin amino acid sequence and phi/psi angles, followed by truncated Newton energy minimization and determination of the lowest frequency normal mode. (wustl.edu)
  • There are three well-characterized families of opioid peptides produced by the body: enkephalins, B-endorphin, and dynorphins. (wikipedia.org)
  • This research has suggested that, as part of the stress response, several met-enkephalin analogs have increased activity in the hippocampus, while leu-enkephalin analogs as well as somatostatins are downregulated during stress. (wikipedia.org)
  • abstract = "To determine the cross tolerance to the antinociceptive effects of μ and δ opioids in the spinal cord, rats received a 7-day infusion of one of three concentrations each of morphine (2, 6, or 20 nmol/h) or D-ala2-D-leu5- enkephalin (DADLE) (2, 6, or 20 nmol/h). (okstate.edu)
  • Incubation of radioactively labeled enkephalin with serum components or chromaffin granule components in vitro provided evidence that there are specific constituents which bind enkephalins and may affect their degradation. (elsevierpure.com)
  • The present study shows the feasibility of the recently reported on-line coupled size exclusion chromatography (SEC) and reversed phase liquid chromatography (RP-LC) separation system for the quantitation of structural related peptides in biological matrices, as demonstrated for a number of enkephalins in CSF. (vu.nl)
  • Post-mortem neuropathological material from 3 patients with striato-pallidal infarction provided the first immunohistochemical evidence for substance P- and enkephalin-containing nerve fibre projections from the striato-pallidum to the substantia nigra in the human. (northwestern.edu)
  • The nigra corresponding to the normal side showed abundant substance P and enkephalin immunoreactivity whose patterns of immunostaining were notably similar. (northwestern.edu)
  • In contrast, the substantia nigra ipsilateral to the striato-pallidal infarction showed a decrease in substance P and enkephalin immunoreactivity which was proportional to the extent of the infarction. (northwestern.edu)
  • This suggests that much of the substance P and enkephalin immunoreactivity in the nigra is present in nerve fibres projecting from the striato-pallidum. (northwestern.edu)
  • Furthermore, the similar distribution of remaining substance P and enkephalin immunoreactivity in corresponding areas of the nigra of the infarcted side indicates that the origins and/or projections of nerve fibres containing these two neuropeptides may be closely approximated anatomically. (northwestern.edu)
  • One such substance is a peptide called enkephalin, a naturally occurring opioid-like substance that is released by neurons in the central nervous system. (blbchronicpain.co.uk)
  • Researchers in France have been successful in coating enkephalin in nanoparticles, likened to a type of biological fat. (blbchronicpain.co.uk)
  • An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. (wikipedia.org)
  • The proopiomelanocortin gene (POMC) also contains the met-enkephalin sequence on the N-terminus of beta-endorphin, but the endorphin peptide is not processed into enkephalin. (wikipedia.org)
  • Studies show marked increases in beta endorphin and met-enkephalin with low-frequency TENS, with demonstrated reversal of the antinociceptive effects by naloxone. (medscape.com)
  • Met5-enkephalin (ME)-induced cardioprotection occurs via epidermal growth factor receptor (EGFR) transactivation with the subsequent activation of phosphatidylinositol 3-kinase (PI3K). (biongenex.com)
  • If the supply of opiates is cut off, pain returns, since there are no enkephalins left to deal with it. (la-articles.org.uk)
  • Plasma of patients with various grades of HE and met-enkephalin and leu-enkephalin levels compared to control subjects and cirrhotic have been found to be higher in patients patients. (who.int)
  • the leu-enkephalin peptide sequence is coded for by both the enkephalin gene and the dynorphin gene. (wikipedia.org)
  • The present report employs in situ hybridization of the 2 opioid precursor mRNAs coupled with quantitative measurements of 2 peptides derived from the prodynorphin and proenkephalin precursor proteins: dynorphin A 1-8 and [Met 5 ]-enkephalin-Arg 6 -Gly 7 -Leu 8 . (nih.gov)
  • Conversely, hippocampal levels of immunoreactive dynorphin A (1-8) and [Met]5-enkephalin were decreased as a function of seizure frequency and intensity. (nih.gov)
  • There are three well-characterized families of opioid peptides produced by the body: enkephalins, B-endorphin, and dynorphins. (wikipedia.org)
  • 10-year Global therapeutic forecast for MENK (met5-enkephalin) indicated for Pancreatic Cancer. (blueprintorphan.com)
  • 2. Methionine enkephalin (MENK) mounts antitumor effect via regulating dendritic cells (DCs). (nih.gov)
  • 5. Immunotherapy of cancer via mediation of cytotoxic T lymphocytes by methionine enkephalin (MENK). (nih.gov)
  • 8. Methionine enkephalin (MENK) inhibits human gastric cancer through regulating tumor associated macrophages (TAMs) and PI3K/AKT/mTOR signaling pathway inside cancer cells. (nih.gov)
  • 9. Novel modulation on myeloid-derived suppressor cells (MDSCs) by methionine encephalin (MENK). (nih.gov)
  • 10. Methionine enkephalin (MENK) inhibits tumor growth through regulating CD4+Foxp3+ regulatory T cells (Tregs) in mice. (nih.gov)
  • 14. Methionine enkephalin (MENK) regulates the immune pathogenesis of type 2 diabetes mellitus via the IL-33/ST2 pathway. (nih.gov)
  • 15. Macrophage polarization induced by neuropeptide methionine enkephalin (MENK) promotes tumoricidal responses. (nih.gov)
  • 16. Induction on differentiation and modulation of bone marrow progenitor of dendritic cell by methionine enkephalin (MENK). (nih.gov)
  • 20. Methionine enkephalin (MENK) improved the functions of bone marrow-derived dendritic cells (BMDCs) loaded with antigen. (nih.gov)
  • Our most advanced clinical programs involve immunotherapy with met-enkephalin ("MENK") (sometimes referred to as opioid growth factor ("OGF")) and our Low Dose Naltrexone product ("LDN") or Lodonal™, which have been shown to stimulate the immune system even in patients with advanced cancer. (prnewswire.com)
  • An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. (wikipedia.org)
  • Enkephalins are pentapeptides involved in regulating nociception in the body. (anaspec.com)
  • The proopiomelanocortin gene (POMC) also contains the met-enkephalin sequence on the N-terminus of beta-endorphin, but the endorphin peptide is not processed into enkephalin. (wikipedia.org)
  • Substitution of the meta-position of Phe4 of Leu5-enkephalin provided high-affinity ligands with varying levels of selectivity and bias at both the δOR and µOR and improved peptide stability, while substitution with picoline derivatives produced lower-affinity ligands with G protein biases at both receptors. (ku.edu)
  • In the same experiment, immunoreactive enkephalin peptide levels, although somewhat decreased at 3-12 h, began to increase between 12 and 24 h after injection, and were still rising at 72 h. (nih.gov)
  • 11. Inhibition of the growth of human melanoma cells by methionine enkephalin. (nih.gov)
  • 13. A novel mechanism of lung cancer inhibition by methionine enkephalin through remodeling the immune status of the tumor microenvironment. (nih.gov)
  • Maldonado R.. The inhibition of enkephalin catabolism by dual enkephalinase inhibitor: A novel possible therapeutic approach for opioid use disorders . (upf.edu)
  • It differs from LEU-ENKEPHALIN by the amino acid METHIONINE in position 5. (reference.md)
  • 1. The paradoxical role of methionine enkephalin in tumor responses. (nih.gov)
  • 3. Methionine enkephalin, its role in immunoregulation and cancer therapy. (nih.gov)
  • 6. Methionine enkephalin inhibits colorectal cancer by remodeling the immune status of the tumor microenvironment. (nih.gov)
  • 7. CD10 enhances metastasis of colorectal cancer by abrogating the anti-tumoural effect of methionine-enkephalin in the liver. (nih.gov)
  • 12. Methionine enkephalin inhibits influenza A virus infection through upregulating antiviral state in RAW264.7 cells. (nih.gov)
  • 17. Methionine enkephalin regulates microglia polarization and function. (nih.gov)
  • They injected a synthetic analogue of enkephalin (called DAMGO ) into this same region of the brain and then let the rats eat as many M&M's as they wanted. (smithsonianmag.com)
  • Linden D, Martinez Jr JL (1986) Leu-enkephalin impairs memory of an appetitive maze response in mice. (springer.com)
  • Enkephalin is also considered a neuropeptide, which in the human body performs as an important signaling molecule in the brain. (wikipedia.org)
  • Studies show marked increases in beta endorphin and met-enkephalin with low-frequency TENS, with demonstrated reversal of the antinociceptive effects by naloxone. (medscape.com)
  • To this end, we explored substitution at the Phe4 position of Leu5-enkephalin for its ability to modulate receptor function and selectivity. (ku.edu)
  • A single residue, Lys108, of the delta-opioid receptor prevents the mu-opioid-selective ligand [D-Ala2,N-MePhe4,Gly-ol5]enkephalin from binding to the delta-opioid receptor. (aspetjournals.org)
  • The enkephalins are known to regulate many physiological functions, including reproduction in vertebrates . (bvsalud.org)
  • In the myenteric plexus (a network of nerve fibres in the wall of the intestine), there are several other messenger substances and receptors capable of modulating smooth muscle activity, including somatostatin , serotonin (5-hydroxytryptamine), and the enkephalins. (britannica.com)
  • In the first phase of the experiment, the team simply monitored the neostriatum while offering the rats M&M's, tracking levels of the chemical enkephalin in this part of the rats' brains via implanted probes. (smithsonianmag.com)
  • After eating M&M's, enkephalin levels in the rats' neostriatums spiked. (smithsonianmag.com)
  • It seems likely that our enkephalin findings in rats mean that this neurotransmitter may drive some forms of over-consumption and addiction in people. (smithsonianmag.com)
  • The receptors for enkephalin are the delta opioid receptors and mu opioid receptors. (wikipedia.org)
  • Mouse striatum stained with D2 cell marker Enkephalin (RA14124) in green and with neuronal marker NeuN in red courtesy of Dr Heike Rebholz of City College of New York. (neuromics.com)
  • Overall, these favorable substitutions at the meta-position of Phe4 may be combined with other modifications to Leu5-enkephalin to deliver improved agonists with finely tuned potency, selectivity, bias and drug-like properties. (ku.edu)