A deaminated metabolite of LEVODOPA.
Homovanillic acid (HVA) is a major metabolite of dopamine, formed in the body through the catabolic breakdown of this neurotransmitter by the enzyme catechol-O-methyltransferase and then further metabolized in the liver before excretion in urine.
Derivatives of phenylacetic acid. Included under this heading are a variety of acid forms, salts, esters, and amides that contain the benzeneacetic acid structure. Note that this class of compounds should not be confused with derivatives of phenyl acetate, which contain the PHENOL ester of ACETIC ACID.
One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.
Biogenic amines having only one amine moiety. Included in this group are all natural monoamines formed by the enzymatic decarboxylation of natural amino acids.
Homogentisic acid is an organic compound that is an intermediate metabolite in the catabolic pathway of tyrosine and phenylalanine, and its accumulation in the body can lead to a rare genetic disorder known as alkaptonuria.
Hydroxyindoleacetic acid (5HIAA) is a major metabolite of serotonin, a neurotransmitter, formed by the action of monoamine oxidase and aldehyde dehydrogenase, and its measurement in urine is often used as a biomarker for serotonin synthesis in clinical and research settings.
Alicyclic hydrocarbons in which three or more of the carbon atoms in each molecule are united in a ring structure and each of the ring carbon atoms is joined to two hydrogen atoms or alkyl groups. The simplest members are cyclopropane (C3H6), cyclobutane (C4H8), cyclohexane (C6H12), and derivatives of these such as methylcyclohexane (C6H11CH3). (From Sax, et al., Hawley's Condensed Chemical Dictionary, 11th ed)
A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.
A group of naturally occurring amines derived by enzymatic decarboxylation of the natural amino acids. Many have powerful physiological effects (e.g., histamine, serotonin, epinephrine, tyramine). Those derived from aromatic amino acids, and also their synthetic analogs (e.g., amphetamine), are of use in pharmacology.
The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system.
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.
A group of 1,2-benzenediols that contain the general formula R-C6H5O2.
An inhibitor of DOPA DECARBOXYLASE that does not enter the central nervous system. It is often given with LEVODOPA in the treatment of parkinsonism to prevent the conversion of levodopa to dopamine in the periphery, thereby increasing the amount that reaches the central nervous system and reducing the required dose. It has no antiparkinson actions when given alone.
An isoquinoline derivative that prevents dopamine reuptake into synaptosomes. The maleate was formerly used in the treatment of depression. It was withdrawn worldwide in 1986 due to the risk of acute hemolytic anemia with intravascular hemolysis resulting from its use. In some cases, renal failure also developed. (From Martindale, The Extra Pharmacopoeia, 30th ed, p266)
A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.
A technique for measuring extracellular concentrations of substances in tissues, usually in vivo, by means of a small probe equipped with a semipermeable membrane. Substances may also be introduced into the extracellular space through the membrane.
Vanilmandelic acid (VMA) is a major metabolite of catecholamines, specifically normetanephrine and metanephrine, which are produced by the adrenal gland and can be measured in urine to help diagnose pheochromocytoma or neuroblastoma.
Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.
Synthesized from endogenous epinephrine and norepinephrine in vivo. It is found in brain, blood, CSF, and urine, where its concentrations are used to measure catecholamine turnover.
A process of selective diffusion through a membrane. It is usually used to separate low-molecular-weight solutes which diffuse through the membrane from the colloidal and high-molecular-weight solutes which do not. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A monoamine oxidase inhibitor with antihypertensive properties.
A chemically heterogeneous group of drugs that have in common the ability to block oxidative deamination of naturally occurring monoamines. (From Gilman, et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p414)
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC 1.14.16.2.
The prototypical uricosuric agent. It inhibits the renal excretion of organic anions and reduces tubular reabsorption of urate. Probenecid has also been used to treat patients with renal impairment, and, because it reduces the renal tubular excretion of other drugs, has been used as an adjunct to antibacterial therapy.
An enzyme that catalyzes the oxidative deamination of naturally occurring monoamines. It is a flavin-containing enzyme that is localized in mitochondrial membranes, whether in nerve terminals, the liver, or other organs. Monoamine oxidase is important in regulating the metabolic degradation of catecholamines and serotonin in neural or target tissues. Hepatic monoamine oxidase has a crucial defensive role in inactivating circulating monoamines or those, such as tyramine, that originate in the gut and are absorbed into the portal circulation. (From Goodman and Gilman's, The Pharmacological Basis of Therapeutics, 8th ed, p415) EC 1.4.3.4.
An alkaloid that has actions similar to NICOTINE on nicotinic cholinergic receptors but is less potent. It has been proposed for a variety of therapeutic uses including in respiratory disorders, peripheral vascular disorders, insomnia, and smoking cessation.
A phenyl-piperidinyl-butyrophenone that is used primarily to treat SCHIZOPHRENIA and other PSYCHOSES. It is also used in schizoaffective disorder, DELUSIONAL DISORDERS, ballism, and TOURETTE SYNDROME (a drug of choice) and occasionally as adjunctive therapy in INTELLECTUAL DISABILITY and the chorea of HUNTINGTON DISEASE. It is a potent antiemetic and is used in the treatment of intractable HICCUPS. (From AMA Drug Evaluations Annual, 1994, p279)
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
An enzyme group with broad specificity. The enzymes decarboxylate a range of aromatic amino acids including dihydroxyphenylalanine (DOPA DECARBOXYLASE); TRYPTOPHAN; and HYDROXYTRYPTOPHAN.
An indirect sympathomimetic. Tyramine does not directly activate adrenergic receptors, but it can serve as a substrate for adrenergic uptake systems and monoamine oxidase so it prolongs the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals. Tyramine may be a neurotransmitter in some invertebrate nervous systems.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
A neurotransmitter analogue that depletes noradrenergic stores in nerve endings and induces a reduction of dopamine levels in the brain. Its mechanism of action is related to the production of cytolytic free-radicals.
Collection of pleomorphic cells in the caudal part of the anterior horn of the LATERAL VENTRICLE, in the region of the OLFACTORY TUBERCLE, lying between the head of the CAUDATE NUCLEUS and the ANTERIOR PERFORATED SUBSTANCE. It is part of the so-called VENTRAL STRIATUM, a composite structure considered part of the BASAL GANGLIA.
The phylogenetically newer part of the CORPUS STRIATUM consisting of the CAUDATE NUCLEUS and PUTAMEN. It is often called simply the striatum.
Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.
An alkaloid found in the roots of Rauwolfia serpentina and R. vomitoria. Reserpine inhibits the uptake of norepinephrine into storage vesicles resulting in depletion of catecholamines and serotonin from central and peripheral axon terminals. It has been used as an antihypertensive and an antipsychotic as well as a research tool, but its adverse effects limit its clinical use.
The black substance in the ventral midbrain or the nucleus of cells containing the black substance. These cells produce DOPAMINE, an important neurotransmitter in regulation of the sensorimotor system and mood. The dark colored MELANIN is a by-product of dopamine synthesis.
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.
A central nervous system stimulant and sympathomimetic with actions and uses similar to DEXTROAMPHETAMINE. The smokable form is a drug of abuse and is referred to as crank, crystal, crystal meth, ice, and speed.
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.
The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
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 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.
Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.
A progressive, degenerative neurologic disease characterized by a TREMOR that is maximal at rest, retropulsion (i.e. a tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. LEWY BODIES are present in the substantia nigra and locus coeruleus but may also be found in a related condition (LEWY BODY DISEASE, DIFFUSE) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)
The physical activity of a human or an animal as a behavioral phenomenon.
The observable response an animal makes to any situation.
Any drugs that are used for their effects on dopamine receptors, on the life cycle of dopamine, or on the survival of dopaminergic neurons.

3,4-Dihydroxyphenylacetic Acid (3,4-DOPAC) is a major metabolite of dopamine, which is a neurotransmitter in the brain. Dopamine is metabolized by the enzyme monoamine oxidase to form dihydroxyphenylacetaldehyde, which is then further metabolized to 3,4-DOPAC by the enzyme aldehyde dehydrogenase.

3,4-DOPAC is found in the urine and can be used as a marker for dopamine turnover in the brain. Changes in the levels of 3,4-DOPAC have been associated with various neurological disorders such as Parkinson's disease and schizophrenia. Additionally, 3,4-DOPAC has been shown to have antioxidant properties and may play a role in protecting against oxidative stress in the brain.

Homovanillic acid (HVA) is a major metabolite of dopamine, a neurotransmitter in the human body. It is formed in the body when an enzyme called catechol-O-methyltransferase (COMT) breaks down dopamine. HVA can be measured in body fluids such as urine, cerebrospinal fluid, and plasma to assess the activity of dopamine and the integrity of the dopaminergic system. Increased levels of HVA are associated with certain neurological disorders, including Parkinson's disease, while decreased levels may indicate dopamine deficiency or other conditions affecting the nervous system.

Phenylacetates are a group of organic compounds that contain a phenyl group (a benzene ring with a hydroxyl group) and an acetic acid group. In the context of medicine, sodium phenylacetate is used in the treatment of certain metabolic disorders, such as urea cycle disorders, to help remove excess ammonia from the body. It does this by conjugating with glycine to form phenylacetylglutamine, which can then be excreted in the urine.

It is important to note that the use of phenylacetates should be under the supervision of a medical professional, as improper use or dosage can lead to serious side effects.

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

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

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

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

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

Examples of biogenic monoamines include:

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

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

Homogentisic acid is not a medical condition, but rather an organic compound that plays a role in certain metabolic processes. It is a breakdown product of the amino acid tyrosine, and is normally further metabolized by the enzyme homogentisate 1,2-dioxygenase.

In some individuals, a genetic mutation can result in a deficiency of this enzyme, leading to a condition called alkaptonuria. In alkaptonuria, homogentisic acid accumulates in the body and can cause damage to connective tissues, joints, and other organs over time. Symptoms may include dark urine, arthritis, and pigmentation of the ears and eyes. However, it is important to note that alkaptonuria is a rare condition, affecting only about 1 in 250,000 people worldwide.

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

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

Cycloparaffins, also known as naphthenes or cycloalkanes, are a type of hydrocarbon molecule that contain one or more closed rings of carbon atoms. These rings can be saturated, meaning that they contain only single bonds between the carbon atoms, and may also contain one or more alkyl substituents.

The term "cycloparaffin" is used in the context of organic chemistry and petroleum refining to describe a specific class of hydrocarbons. In medical terminology, cycloparaffins are not typically referenced directly, but they may be relevant in certain contexts, such as in discussions of industrial chemicals or environmental exposures.

Cycloparaffins can be found in various sources, including crude oil and natural gas, and they are often used as feedstocks in the production of various chemicals and materials. They are also found in some foods, such as vegetable oils and animal fats, and may be present in trace amounts in some medications or medical devices.

While cycloparaffins themselves are not typically considered to have direct medical relevance, exposure to certain types of cycloparaffins or their derivatives may be associated with various health effects, depending on the level and duration of exposure. For example, some cycloparaffin-derived chemicals have been linked to respiratory irritation, skin and eye irritation, and potential developmental toxicity. However, it is important to note that these effects are typically associated with high levels of exposure in occupational or industrial settings, rather than with normal environmental or dietary exposures.

Dihydroxyphenylalanine is not a medical term per se, but it is a chemical compound that is often referred to in the context of biochemistry and neuroscience. It is also known as levodopa or L-DOPA for short.

L-DOPA is a precursor to dopamine, a neurotransmitter that plays a critical role in regulating movement, emotion, and cognition. In the brain, L-DOPA is converted into dopamine through the action of an enzyme called tyrosine hydroxylase.

L-DOPA is used medically to treat Parkinson's disease, a neurological disorder characterized by motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement). In Parkinson's disease, the dopamine-producing neurons in the brain gradually degenerate, leading to a deficiency of dopamine. By providing L-DOPA as a replacement therapy, doctors can help alleviate some of the symptoms of the disease.

It is important to note that L-DOPA has potential side effects and risks, including nausea, dizziness, and behavioral changes. Long-term use of L-DOPA can also lead to motor complications such as dyskinesias (involuntary movements) and fluctuations in response to the medication. Therefore, it is typically used in combination with other medications and under the close supervision of a healthcare provider.

Biogenic amines are organic compounds that are derived from the metabolic pathways of various biological organisms, including humans. They are formed by the decarboxylation of amino acids, which are the building blocks of proteins. Some examples of biogenic amines include histamine, serotonin, dopamine, and tyramine.

Histamine is a biogenic amine that plays an important role in the immune system's response to foreign invaders, such as allergens. It is also involved in regulating stomach acid production and sleep-wake cycles. Serotonin is another biogenic amine that acts as a neurotransmitter, transmitting signals between nerve cells in the brain. It is involved in regulating mood, appetite, and sleep.

Dopamine is a biogenic amine that functions as a neurotransmitter and is involved in reward and pleasure pathways in the brain. Tyramine is a biogenic amine that is found in certain foods, such as aged cheeses and fermented soy products. It can cause an increase in blood pressure when consumed in large quantities.

Biogenic amines can have various effects on the body, depending on their type and concentration. In general, they play important roles in many physiological processes, but high levels of certain biogenic amines can be harmful and may cause symptoms such as headache, nausea, and hypertension.

Levodopa, also known as L-dopa, is a medication used primarily in the treatment of Parkinson's disease. It is a direct precursor to the neurotransmitter dopamine and works by being converted into dopamine in the brain, helping to restore the balance between dopamine and other neurotransmitters. This helps alleviate symptoms such as stiffness, tremors, spasms, and poor muscle control. Levodopa is often combined with carbidopa (a peripheral decarboxylase inhibitor) to prevent the conversion of levodopa to dopamine outside of the brain, reducing side effects like nausea and vomiting.

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.

Catechols are a type of chemical compound that contain a benzene ring with two hydroxyl groups (-OH) attached to it in the ortho position. The term "catechol" is often used interchangeably with "ortho-dihydroxybenzene." Catechols are important in biology because they are produced through the metabolism of certain amino acids, such as phenylalanine and tyrosine, and are involved in the synthesis of various neurotransmitters and hormones. They also have antioxidant properties and can act as reducing agents. In chemistry, catechols can undergo various reactions, such as oxidation and polymerization, to form other classes of compounds.

Benserazide is a type of medication called an inhibitor of peripheral aromatic amino acid decarboxylase. It is often used in combination with levodopa to treat Parkinson's disease. Benserazide works by preventing the conversion of levodopa to dopamine outside of the brain, which helps to reduce the side effects of levodopa and increase the amount of dopamine that reaches the brain. This can help to improve the symptoms of Parkinson's disease, such as stiffness, tremors, and difficulty with movement.

Benserazide is available in combination with levodopa under the brand name Madopar. It is taken orally, usually in the form of tablets. The specific dosage of benserazide will depend on the individual's needs and should be determined by a healthcare professional.

It is important to note that benserazide can interact with other medications, so it is important to inform your doctor about all the medications you are taking before starting treatment with benserazide. Additionally, benserazide may cause side effects, such as nausea, dizziness, and dry mouth. If you experience any severe or persistent side effects while taking benserazide, you should contact your healthcare provider.

Nomifensine is a medication that was previously used in the treatment of depression, but it is no longer available in many countries due to safety concerns. It is a non-tricyclic antidepressant that works by inhibiting the reuptake of dopamine and noradrenaline, which helps to increase the levels of these neurotransmitters in the brain and improve mood.

The medical definition of Nomifensine is:

"Nomifensine is a non-tricyclic antidepressant that is a potent inhibitor of dopamine and noradrenaline reuptake, with minimal effects on serotonin reuptake. It was used in the treatment of depression but has been withdrawn from the market due to safety concerns."

It's important to note that Nomifensine should only be taken under the supervision of a medical professional, and it is not available in many countries due to its potential for causing serious side effects such as liver toxicity and the risk of developing a rare but potentially fatal condition called hemolytic anemia.

Catecholamines are a group of hormones and neurotransmitters that are derived from the amino acid tyrosine. The most well-known catecholamines are dopamine, norepinephrine (also known as noradrenaline), and epinephrine (also known as adrenaline). These hormones are produced by the adrenal glands and are released into the bloodstream in response to stress. They play important roles in the "fight or flight" response, increasing heart rate, blood pressure, and alertness. In addition to their role as hormones, catecholamines also function as neurotransmitters, transmitting signals in the nervous system. Disorders of catecholamine regulation can lead to a variety of medical conditions, including hypertension, mood disorders, and neurological disorders.

Microdialysis is a minimally invasive technique used in clinical and research settings to continuously monitor the concentration of various chemicals, such as neurotransmitters, drugs, or metabolites, in biological fluids (e.g., extracellular fluid of tissues, blood, or cerebrospinal fluid). This method involves inserting a small, flexible catheter with a semipermeable membrane into the region of interest. A physiological solution is continuously perfused through the catheter, allowing molecules to diffuse across the membrane based on their concentration gradient. The dialysate that exits the catheter is then collected and analyzed for target compounds using various analytical techniques (e.g., high-performance liquid chromatography, mass spectrometry).

In summary, microdialysis is a valuable tool for monitoring real-time changes in chemical concentrations within biological systems, enabling better understanding of physiological processes or pharmacokinetic properties of drugs.

Vanilmandelic acid (VMA) is a metabolite produced in the body as a result of the breakdown of catecholamines, which are hormones such as dopamine, norepinephrine, and epinephrine. Specifically, VMA is the major end product of epinephrine and norepinephrine metabolism.

In clinical medicine, measurement of VMA in urine is often used as a diagnostic test for pheochromocytoma, a rare tumor that arises from the chromaffin cells of the adrenal gland and can cause excessive production of catecholamines. Elevated levels of VMA in the urine may indicate the presence of a pheochromocytoma or other conditions associated with increased catecholamine secretion, such as neuroblastoma or ganglioneuroma.

It's important to note that while VMA is a useful diagnostic marker for pheochromocytoma and related conditions, it is not specific to these disorders and can be elevated in other medical conditions as well. Therefore, the test should be interpreted in conjunction with other clinical findings and diagnostic tests.

Brain chemistry refers to the chemical processes that occur within the brain, particularly those involving neurotransmitters, neuromodulators, and neuropeptides. These chemicals are responsible for transmitting signals between neurons (nerve cells) in the brain, allowing for various cognitive, emotional, and physical functions.

Neurotransmitters are chemical messengers that transmit signals across the synapse (the tiny gap between two neurons). Examples of neurotransmitters include dopamine, serotonin, norepinephrine, GABA (gamma-aminobutyric acid), and glutamate. Each neurotransmitter has a specific role in brain function, such as regulating mood, motivation, attention, memory, and movement.

Neuromodulators are chemicals that modify the effects of neurotransmitters on neurons. They can enhance or inhibit the transmission of signals between neurons, thereby modulating brain activity. Examples of neuromodulators include acetylcholine, histamine, and substance P.

Neuropeptides are small protein-like molecules that act as neurotransmitters or neuromodulators. They play a role in various physiological functions, such as pain perception, stress response, and reward processing. Examples of neuropeptides include endorphins, enkephalins, and oxytocin.

Abnormalities in brain chemistry can lead to various neurological and psychiatric conditions, such as depression, anxiety disorders, schizophrenia, Parkinson's disease, and Alzheimer's disease. Understanding brain chemistry is crucial for developing effective treatments for these conditions.

Methoxyhydroxyphenylglycol (MHPG) is a major metabolite of the neurotransmitter norepinephrine, which is synthesized in the body from the amino acid tyrosine. Norepinephrine plays important roles in various physiological functions such as the cardiovascular system, respiratory system, and central nervous system. MHPG is formed when norepinephrine is metabolized by enzymes called catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO).

MHPG is primarily found in the urine, and its levels can be measured to assess norepinephrine turnover in the body. Changes in MHPG levels have been associated with various medical conditions, including depression, anxiety disorders, and neurodegenerative diseases such as Parkinson's disease. However, the clinical utility of measuring MHPG levels is still a subject of ongoing research and debate.

Dialysis is a medical treatment that is used to remove waste and excess fluid from the blood when the kidneys are no longer able to perform these functions effectively. This life-sustaining procedure uses a specialized machine, called a dialyzer or artificial kidney, to filter the blood outside of the body and return clean, chemically balanced blood back into the body.

There are two main types of dialysis: hemodialysis and peritoneal dialysis.

1. Hemodialysis: In this method, a patient's blood is passed through an external filter (dialyzer) that removes waste products, toxins, and excess fluids. The cleaned blood is then returned to the body with the help of a specialized machine. Hemodialysis typically requires access to a large vein, often created by a surgical procedure called an arteriovenous (AV) fistula or graft. Hemodialysis sessions usually last for about 3-5 hours and are performed three times a week in a clinical setting, such as a dialysis center or hospital.
2. Peritoneal Dialysis: This method uses the lining of the patient's own abdomen (peritoneum) as a natural filter to clean the blood. A sterile dialysate solution is introduced into the peritoneal cavity via a permanently implanted catheter. The solution absorbs waste products and excess fluids from the blood vessels lining the peritoneum through a process called diffusion. After a dwell time, usually several hours, the used dialysate is drained out and replaced with fresh dialysate. This process is known as an exchange and is typically repeated multiple times throughout the day or night, depending on the specific type of peritoneal dialysis (continuous ambulatory peritoneal dialysis or automated peritoneal dialysis).

Both methods have their advantages and disadvantages, and the choice between them depends on various factors, such as a patient's overall health, lifestyle, and personal preferences. Dialysis is a life-saving treatment for people with end-stage kidney disease or severe kidney dysfunction, allowing them to maintain their quality of life and extend their lifespan until a kidney transplant becomes available or their kidney function improves.

Pargyline is an antihypertensive drug and a irreversible monoamine oxidase inhibitor (MAOI) of type B. It works by blocking the breakdown of certain chemicals in the brain, such as neurotransmitters, which can help improve mood and behavior in people with depression.

Pargyline is not commonly used as a first-line treatment for depression due to its potential for serious side effects, including interactions with certain foods and medications that can lead to dangerously high blood pressure. It is also associated with a risk of serotonin syndrome when taken with selective serotonin reuptake inhibitors (SSRIs) or other drugs that increase serotonin levels in the brain.

Pargyline is available only through a prescription and should be used under the close supervision of a healthcare provider.

Monoamine oxidase inhibitors (MAOIs) are a class of drugs that work by blocking the action of monoamine oxidase, an enzyme found in the brain and other organs of the body. This enzyme is responsible for breaking down certain neurotransmitters, such as serotonin, dopamine, and norepinephrine, which are chemicals that transmit signals in the brain.

By inhibiting the action of monoamine oxidase, MAOIs increase the levels of these neurotransmitters in the brain, which can help to alleviate symptoms of depression and other mood disorders. However, MAOIs also affect other chemicals in the body, including tyramine, a substance found in some foods and beverages, as well as certain medications. As a result, MAOIs can have serious side effects and interactions with other substances, making them a less commonly prescribed class of antidepressants than other types of drugs.

MAOIs are typically used as a last resort when other treatments for depression have failed, due to their potential for dangerous interactions and side effects. They require careful monitoring and dosage adjustment by a healthcare provider, and patients must follow strict dietary restrictions while taking them.

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

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

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

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

Tyrosine 3-Monooxygenase (also known as Tyrosinase or Tyrosine hydroxylase) is an enzyme that plays a crucial role in the synthesis of catecholamines, which are neurotransmitters and hormones in the body. This enzyme catalyzes the conversion of the amino acid L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by adding a hydroxyl group to the 3rd carbon atom of the tyrosine molecule.

The reaction is as follows:

L-Tyrosine + O2 + pterin (co-factor) -> L-DOPA + pterin (oxidized) + H2O

This enzyme requires molecular oxygen and a co-factor such as tetrahydrobiopterin to carry out the reaction. Tyrosine 3-Monooxygenase is found in various tissues, including the brain and adrenal glands, where it helps regulate the production of catecholamines like dopamine, norepinephrine, and epinephrine. Dysregulation of this enzyme has been implicated in several neurological disorders, such as Parkinson's disease.

Probenecid is a medication that is primarily used to treat gout and hyperuricemia (high levels of uric acid in the blood). It works by decreasing the production of uric acid in the body and increasing its excretion through the kidneys.

In medical terms, probenecid is a uricosuric agent, which means it increases the urinary excretion of urate, the salt form of uric acid. It does this by inhibiting the reabsorption of urate in the proximal tubules of the kidneys, thereby promoting its elimination in the urine.

Probenecid is also used in conjunction with certain antibiotics, such as penicillin and cephalosporins, to increase their concentration in the body by reducing their excretion by the kidneys. This is known as probenecid-antibiotic interaction.

It's important to note that probenecid should be used under the supervision of a healthcare provider, and its use may be contraindicated in certain medical conditions or in combination with specific medications.

Monoamine oxidase (MAO) is an enzyme found on the outer membrane of mitochondria in cells throughout the body, but primarily in the gastrointestinal tract, liver, and central nervous system. It plays a crucial role in the metabolism of neurotransmitters and dietary amines by catalyzing the oxidative deamination of monoamines. This enzyme exists in two forms: MAO-A and MAO-B, each with distinct substrate preferences and tissue distributions.

MAO-A preferentially metabolizes serotonin, norepinephrine, and dopamine, while MAO-B is mainly responsible for breaking down phenethylamines and benzylamines, as well as dopamine in some cases. Inhibition of these enzymes can lead to increased neurotransmitter levels in the synaptic cleft, which has implications for various psychiatric and neurological conditions, such as depression and Parkinson's disease. However, MAO inhibitors must be used with caution due to their potential to cause serious adverse effects, including hypertensive crises, when combined with certain foods or medications containing dietary amines or sympathomimetic agents.

Lobeline is not a medical term per se, but it is a pharmacological substance with some potential medical applications. Lobeline is an alkaloid compound that can be found in certain plants, including the Indian tobacco plant (Lobelia inflata). It has been used in some over-the-counter and prescription medications as a smoking cessation aid due to its ability to stimulate nicotinic acetylcholine receptors in the brain, which may help reduce cravings for nicotine.

However, it's important to note that the effectiveness of lobeline as a smoking cessation aid is still a matter of debate and further research is needed to fully understand its potential benefits and risks.

Haloperidol is an antipsychotic medication, which is primarily used to treat schizophrenia and symptoms of psychosis, such as delusions, hallucinations, paranoia, or disordered thought. It may also be used to manage Tourette's disorder, tics, agitation, aggression, and hyperactivity in children with developmental disorders.

Haloperidol works by blocking the action of dopamine, a neurotransmitter in the brain, which helps to regulate mood and behavior. It is available in various forms, including tablets, liquid, and injectable solutions. The medication can cause side effects such as drowsiness, restlessness, muscle stiffness, and uncontrolled movements. In rare cases, it may also lead to more serious neurological side effects.

As with any medication, haloperidol should be taken under the supervision of a healthcare provider, who will consider the individual's medical history, current medications, and other factors before prescribing it.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

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

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

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

Aromatic-L-amino-acid decarboxylases (ALADs) are a group of enzymes that play a crucial role in the synthesis of neurotransmitters and biogenic amines in the body. These enzymes catalyze the decarboxylation of aromatic L-amino acids, such as L-dopa, L-tryptophan, and L-phenylalanine, to produce corresponding neurotransmitters or biogenic amines, including dopamine, serotonin, and histamine, respectively.

There are two main types of ALADs in humans: dopa decarboxylase (DDC) and tryptophan hydroxylase (TPH). DDC is responsible for the conversion of L-dopa to dopamine, which is a crucial neurotransmitter involved in movement regulation. TPH, on the other hand, catalyzes the rate-limiting step in serotonin synthesis by converting L-tryptophan to 5-hydroxytryptophan (5-HTP), which is then converted to serotonin by another enzyme called aromatic amino acid decarboxylase.

Deficiencies or mutations in ALADs can lead to various neurological and psychiatric disorders, such as Parkinson's disease, dopa-responsive dystonia, and depression. Therefore, understanding the function and regulation of ALADs is essential for developing effective therapies for these conditions.

Tyramine is not a medical condition but a naturally occurring compound called a biogenic amine, which is formed from the amino acid tyrosine during the fermentation or decay of certain foods. Medically, tyramine is significant because it can interact with certain medications, particularly monoamine oxidase inhibitors (MAOIs), used to treat depression and other conditions.

The interaction between tyramine and MAOIs can lead to a hypertensive crisis, a rapid and severe increase in blood pressure, which can be life-threatening if not treated promptly. Therefore, individuals taking MAOIs are often advised to follow a low-tyramine diet, avoiding foods high in tyramine, such as aged cheeses, cured meats, fermented foods, and some types of beer and wine.

Electrochemistry is a branch of chemistry that deals with the interconversion of electrical energy and chemical energy. It involves the study of chemical processes that cause electrons to move, resulting in the transfer of electrical charge, and the reverse processes by which electrical energy can be used to drive chemical reactions. This field encompasses various phenomena such as the generation of electricity from chemical sources (as in batteries), the electrolysis of substances, and corrosion. Electrochemical reactions are fundamental to many technologies, including energy storage and conversion, environmental protection, and medical diagnostics.

Oxidopamine is not a recognized medical term or a medication commonly used in clinical practice. However, it is a chemical compound that is often used in scientific research, particularly in the field of neuroscience.

Oxidopamine is a synthetic catecholamine that can be selectively taken up by dopaminergic neurons and subsequently undergo oxidation, leading to the production of reactive oxygen species. This property makes it a useful tool for studying the effects of oxidative stress on dopaminergic neurons in models of Parkinson's disease and other neurological disorders.

In summary, while not a medical definition per se, oxidopamine is a chemical compound used in research to study the effects of oxidative stress on dopaminergic neurons.

The nucleus accumbens is a part of the brain that is located in the ventral striatum, which is a key region of the reward circuitry. It is made up of two subregions: the shell and the core. The nucleus accumbens receives inputs from various sources, including the prefrontal cortex, amygdala, and hippocampus, and sends outputs to the ventral pallidum and other areas.

The nucleus accumbens is involved in reward processing, motivation, reinforcement learning, and addiction. It plays a crucial role in the release of the neurotransmitter dopamine, which is associated with pleasure and reinforcement. Dysfunction in the nucleus accumbens has been implicated in various neurological and psychiatric conditions, including substance use disorders, depression, and obsessive-compulsive disorder.

The neostriatum is a component of the basal ganglia, a group of subcortical nuclei in the brain that are involved in motor control, procedural learning, and other cognitive functions. It is composed primarily of two types of neurons: medium spiny neurons and aspiny interneurons. The neostriatum receives input from various regions of the cerebral cortex and projects to other parts of the basal ganglia, forming an important part of the cortico-basal ganglia-thalamo-cortical loop.

In medical terminology, the neostriatum is often used interchangeably with the term "striatum," although some sources reserve the term "neostriatum" for the caudate nucleus and putamen specifically, while using "striatum" to refer to the entire structure including the ventral striatum (also known as the nucleus accumbens).

Damage to the neostriatum has been implicated in various neurological conditions, such as Huntington's disease and Parkinson's disease.

The hypothalamus is a small, vital region of the brain that lies just below the thalamus and forms part of the limbic system. It plays a crucial role in many important functions including:

1. Regulation of body temperature, hunger, thirst, fatigue, sleep, and circadian rhythms.
2. Production and regulation of hormones through its connection with the pituitary gland (the hypophysis). It controls the release of various hormones by producing releasing and inhibiting factors that regulate the anterior pituitary's function.
3. Emotional responses, behavior, and memory formation through its connections with the limbic system structures like the amygdala and hippocampus.
4. Autonomic nervous system regulation, which controls involuntary physiological functions such as heart rate, blood pressure, and digestion.
5. Regulation of the immune system by interacting with the autonomic nervous system.

Damage to the hypothalamus can lead to various disorders like diabetes insipidus, growth hormone deficiency, altered temperature regulation, sleep disturbances, and emotional or behavioral changes.

Reserpine is an alkaloid derived from the Rauwolfia serpentina plant, which has been used in traditional medicine for its sedative and hypotensive effects. In modern medicine, reserpine is primarily used to treat hypertension (high blood pressure) due to its ability to lower both systolic and diastolic blood pressure.

Reserpine works by depleting catecholamines, including norepinephrine, epinephrine, and dopamine, from nerve terminals in the sympathetic nervous system. This leads to a decrease in peripheral vascular resistance and heart rate, ultimately resulting in reduced blood pressure.

Reserpine is available in various forms, such as tablets or capsules, and is typically administered orally. Common side effects include nasal congestion, dizziness, sedation, and gastrointestinal disturbances like diarrhea and nausea. Long-term use of reserpine may also lead to depression in some individuals. Due to its potential for causing depression, other antihypertensive medications are often preferred over reserpine when possible.

The Substantia Nigra is a region in the midbrain that plays a crucial role in movement control and reward processing. It is composed of two parts: the pars compacta and the pars reticulata. The pars compacta contains dopamine-producing neurons, whose loss or degeneration is associated with Parkinson's disease, leading to motor symptoms such as tremors, rigidity, and bradykinesia.

In summary, Substantia Nigra is a brain structure that contains dopamine-producing cells and is involved in movement control and reward processing. Its dysfunction or degeneration can lead to neurological disorders like Parkinson's 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.

Methamphetamine is a powerful, highly addictive central nervous system stimulant that affects brain chemistry, leading to mental and physical dependence. Its chemical formula is N-methylamphetamine, and it is structurally similar to amphetamine but has additional methyl group, which makes it more potent and longer-lasting.

Methamphetamine exists in various forms, including crystalline powder (commonly called "meth" or "crystal meth") and a rocklike form called "glass." It can be taken orally, snorted, smoked, or injected after being dissolved in water or alcohol.

Methamphetamine use leads to increased levels of dopamine, a neurotransmitter responsible for reward, motivation, and reinforcement, resulting in euphoria, alertness, and energy. Prolonged use can cause severe psychological and physiological harm, including addiction, psychosis, cardiovascular issues, dental problems (meth mouth), and cognitive impairments.

"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.

Epinephrine, also known as adrenaline, is a hormone and a neurotransmitter that is produced in the body. It is released by the adrenal glands in response to stress or excitement, and it prepares the body for the "fight or flight" response. Epinephrine works by binding to specific receptors in the body, which causes a variety of physiological effects, including increased heart rate and blood pressure, improved muscle strength and alertness, and narrowing of the blood vessels in the skin and intestines. It is also used as a medication to treat various medical conditions, such as anaphylaxis (a severe allergic reaction), cardiac arrest, and low blood pressure.

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

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

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

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.

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.

The extracellular space is the region outside of cells within a tissue or organ, where various biological molecules and ions exist in a fluid medium. This space is filled with extracellular matrix (ECM), which includes proteins like collagen and elastin, glycoproteins, and proteoglycans that provide structural support and biochemical cues to surrounding cells. The ECM also contains various ions, nutrients, waste products, signaling molecules, and growth factors that play crucial roles in cell-cell communication, tissue homeostasis, and regulation of cell behavior. Additionally, the extracellular space includes the interstitial fluid, which is the fluid component of the ECM, and the lymphatic and vascular systems, through which cells exchange nutrients, waste products, and signaling molecules with the rest of the body. Overall, the extracellular space is a complex and dynamic microenvironment that plays essential roles in maintaining tissue structure, function, and homeostasis.

Parkinson's disease is a progressive neurodegenerative disorder that affects movement. It is characterized by the death of dopamine-producing cells in the brain, specifically in an area called the substantia nigra. The loss of these cells leads to a decrease in dopamine levels, which results in the motor symptoms associated with Parkinson's disease. These symptoms can include tremors at rest, stiffness or rigidity of the limbs and trunk, bradykinesia (slowness of movement), and postural instability (impaired balance and coordination). In addition to these motor symptoms, non-motor symptoms such as cognitive impairment, depression, anxiety, and sleep disturbances are also common in people with Parkinson's disease. The exact cause of Parkinson's disease is unknown, but it is thought to be a combination of genetic and environmental factors. There is currently no cure for Parkinson's disease, but medications and therapies can help manage the symptoms and improve quality of life.

"Motor activity" is a general term used in the field of medicine and neuroscience to refer to any kind of physical movement or action that is generated by the body's motor system. The motor system includes the brain, spinal cord, nerves, and muscles that work together to produce movements such as walking, talking, reaching for an object, or even subtle actions like moving your eyes.

Motor activity can be voluntary, meaning it is initiated intentionally by the individual, or involuntary, meaning it is triggered automatically by the nervous system without conscious control. Examples of voluntary motor activity include deliberately lifting your arm or kicking a ball, while examples of involuntary motor activity include heartbeat, digestion, and reflex actions like jerking your hand away from a hot stove.

Abnormalities in motor activity can be a sign of neurological or muscular disorders, such as Parkinson's disease, cerebral palsy, or multiple sclerosis. Assessment of motor activity is often used in the diagnosis and treatment of these conditions.

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

Dopamine agents are medications that act on dopamine receptors in the brain. Dopamine is a neurotransmitter, a chemical messenger that transmits signals in the brain and other areas of the body. It plays important roles in many functions, including movement, motivation, emotion, and cognition.

Dopamine agents can be classified into several categories based on their mechanism of action:

1. Dopamine agonists: These medications bind to dopamine receptors and mimic the effects of dopamine. They are used to treat conditions such as Parkinson's disease, restless legs syndrome, and certain types of dopamine-responsive dystonia. Examples include pramipexole, ropinirole, and rotigotine.
2. Dopamine precursors: These medications provide the building blocks for the body to produce dopamine. Levodopa is a commonly used dopamine precursor that is converted to dopamine in the brain. It is often used in combination with carbidopa, which helps to prevent levodopa from being broken down before it reaches the brain.
3. Dopamine antagonists: These medications block the action of dopamine at its receptors. They are used to treat conditions such as schizophrenia and certain types of nausea and vomiting. Examples include haloperidol, risperidone, and metoclopramide.
4. Dopamine reuptake inhibitors: These medications increase the amount of dopamine available in the synapse (the space between two neurons) by preventing its reuptake into the presynaptic neuron. They are used to treat conditions such as attention deficit hyperactivity disorder (ADHD) and depression. Examples include bupropion and nomifensine.
5. Dopamine release inhibitors: These medications prevent the release of dopamine from presynaptic neurons. They are used to treat conditions such as Tourette's syndrome and certain types of chronic pain. Examples include tetrabenazine and deutetrabenazine.

It is important to note that dopamine agents can have significant side effects, including addiction, movement disorders, and psychiatric symptoms. Therefore, they should be used under the close supervision of a healthcare provider.

Both of these substances are degraded to form homovanillic acid (HVA). Both degradations involve the enzymes monoamine oxidase ... 3,4-Dihydroxyphenylacetic acid (DOPAC) is a metabolite of the neurotransmitter dopamine. Dopamine can be metabolized into one ... This product has been synthesized (52% yield) from 4-hydroxyphenylacetic acid via aerobic biotransformation using whole cell ... whereas COMT catalyzes dopamine to 3-MT and MAO catalyzes 3-MT to HVA. The third metabolic end-product of dopamine is ...
HPLC, mass spectrometry, UV data and amino acid analysis are the elements that allow identifying diverse argiotoxins due to ... acetic acid. This group is composed of: Arg-373, Arg-728, Arg-743. It is a low-molecular-weight neurotoxin which has highly ... acetic acid is carried as the chromophore. These molecules are: Arg-630, Arg-658, Arg-659, Arg-744, Arg-759. Pseudoargiopinines ... 3-20. Chemistry and Pharmacology. Academic Press. 1994-06-17. ISBN 9780080865690. Elin, E.A.; de Macedo, B.F.; Onoprienko, V.V ...
Proteinogenic amino acids, Glucogenic amino acids, Ketogenic amino acids, Alpha-Amino acids, Aromatic amino acids, Phenols, ... which in turn can be oxidized by the citric acid cycle or be used for fatty acid synthesis. Phloretic acid is also a urinary ... It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Greek tyrós, meaning cheese, as it ... "Amino Acids - Tyrosine". www.biology.arizona.edu. Retrieved 2018-01-31. Pencharz PB, Hsu JW, Ball RO (June 2007). "Aromatic ...
Determination of free and bound phenolic acids in beer. M. Nardini and A. Ghiselli, Food Chemistry, January 2004, Volume 84, ... Issue 1, Pages 137-143, doi:10.1016/S0308-8146(03)00257-7 Mattioda, Georges; Christidis, Yani (2000). Glyoxylic Acid. p. 2. doi ... 4-Hydroxyphenylacetic acid is a chemical compound found in olive oil and beer. 4-Hydroxyphenylacetic acid is obtained by ... In industry, 4-hydroxyphenylacetic acid is an intermediate used to synthesize atenolol, 3,4-dihydroxyphenylacetic acid, and ...
Some can be useful in measuring rates of metabolic processes (for example, 3,4-dihydroxyphenylacetic acid or 3-aminoisobutyrate ...
Adachi K, Takeda Y, Senoh S, Kita H (December 1964). "Metabolism of P-Hydroxyphenylacetic Acid In Pseudomonas ovalis". ... 147 (3): 844-50. doi:10.1128/JB.147.3.844-850.1981. PMC 216120. PMID 6895079. Kutty RK, Devi NA, Veeraswamy M, Ramesh S, Rao PV ... In enzymology, a 3,4-dihydroxyphenylacetate 2,3-dioxygenase (EC 1.13.11.15) is an enzyme that catalyzes the chemical reaction 3 ... 93 (3): 483-93. doi:10.1016/0304-4165(64)90332-0. PMID 14263147. Barbour MG, Bayly RC (September 1981). "Control of meta- ...
5 (4): 201-217. PMID 1804161. Turova NF, Misionzhnik EI, Ermolina LA, Aziavchik AV, Krasov VA (1988). "[Excretion of monoamines ... 69 (3-4): 653-658. doi:10.1016/S0091-3057(01)00574-3. PMID 11509228. S2CID 32739707. Anderzhanova EA, Afanas'ev II, Kudrin VS, ... 288 (3): 1298-1310. PMID 10027871. Valueva LN, Tozhanova NM (1982). "[Sidnocarb correction of the adverse effects of ... 519-. ISBN 978-3-642-38818-7. Appolonova SA, Shpak AV, Semenov VA (February 2004). "Liquid chromatography-electrospray ...
Nalidixic acid (WIN 18,320) Oxolinic acid Pipemidic acid A-77636 Morris H (October 2015). "Sad Pink Monkey Blues". Harper's ... Amfonelic acid displays no activity in the norepinephrine system. Despite its different mechanism of action, amfonelic acid ... Amfonelic acid has been shown to be neuroprotective against methamphetamine damage to dopamine neurons. It also increases the ... Amfonelic acid (AFA; WIN 25,978) is a research chemical and dopaminergic stimulant with antibiotic properties. Although limited ...
Additionally, anaerobic bacteria in the colon transform primary bile acids into secondary bile acid which has been implicated ... Short-chain fatty acids (SCFAs) have been linked to a decrease in allergic inflammation in asthma while both SCFAs and B ... Gut bacteria metabolites such as short-chain fatty acids (SCFAs), B vitamins and N1, N12-diacetylspermine have also been ... wild-type mice were treated with trinitrobenzen sulphonic acid (TNBS). Thereafter, these mice were given PSA orally. Pro- ...
The molecular formula C8H8O4 (molar mass : 168.15 g/mol, exact mass : 168.042259 u) may refer to: Dehydroacetic acid 3,4- ... Dihydroxyphenylacetic acid 2,6-Dimethoxy-1,4-benzoquinone Homogentisic acid 4-Hydroxymandelic acid 5-Methoxysalicylic acid ... Norcantharidin Orsellinic acid Quinolacetic acid Trihydroxyacetophenones Gallacetophenone (2,3,4-trihydroxyacetophenone) 2,4,6- ... Trihydroxyacetophenone Vanillic acid This set index page lists chemical structure articles associated with the same molecular ...
4-Dihydroxyphenylacetic acid or DOPAC, a metabolite of dopamine Dopa, an angel in Enochian Deleting Online Predators Act of ...
E. globulus bark contains quinic, dihydroxyphenylacetic and caffeic acids, bis(hexahydroxydiphenoyl (HHDP))-glucose, galloyl- ... as well as gallic acid and (+)-catechin can also be isolated.Tricetin is a rare flavone aglycone found in the pollen of members ... bis(HHDP)-glucose, galloyl-HHDP-glucose, isorhamentin-hexoside, quercetin-hexoside, methylellagic acid (EA)-pentose conjugate, ... The hydrolyzable tannins tellimagrandin I, eucalbanin C, 2-O-digalloyl-1,3,4-tri-O-galloyl-β-D-glucose, 6-O-digalloyl-1,2,3-tri ...
Dopamine to dihydroxyphenylacetic acid 3-Methoxytyramine to homovanillic acid Because of the vital role that MAOs play in the ... 13 (3): 207-210. doi:10.1111/j.1440-6055.1974.tb02174.x. S2CID 83731654. Caspi A, McClay J, Moffitt TE, Mill J, Martin J, Craig ... 133 (4): 438-40. doi:10.1176/ajp.133.4.438. PMID 1267046. Meyer JH, Ginovart N, Boovariwala A, Sagrati S, Hussey D, Garcia A, ... 133 (3): 323-6. doi:10.1176/ajp.133.3.323. PMID 943955. Schildkraut JJ, Herzog JM, Orsulak PJ, Edelman SE, Shein HM, Frazier SH ...
The presence of SA 4503 has been linked to increases in the concentration of dopamine and dihydroxyphenylacetic acid (a ... The 3,4-methoxy groups located on the phenethyl group play an important role in σ receptor binding affinity, with alterations ... 131 (3): 596-610. doi:10.1016/j.cell.2007.08.036. PMID 17981125. S2CID 18885068. Weissman, A. D.; Su, T. P.; Hedreen, J. C.; ... 469 (3): 303-308. doi:10.1016/j.neulet.2009.12.013. PMID 20025928. S2CID 20552121. Xu, Rong; Lord, Sarah A.; Peterson, Ryan M ...
... quinic acid MeSH D02.241.511.852 - shikimic acid MeSH D02.241.511.902 - sugar acids MeSH D02.241.511.902.107 - ascorbic acid ... edetic acid MeSH D02.241.081.038.455 - egtazic acid MeSH D02.241.081.038.581 - iodoacetic acid MeSH D02.241.081.038.581.400 - ... hexuronic acids MeSH D02.241.081.844.915.400.500 - iduronic acid MeSH D02.241.081.901.177 - aconitic acid MeSH D02.241.081.901. ... muramic acids MeSH D02.241.081.844.562 - neuraminic acids MeSH D02.241.081.844.562.668 - sialic acids MeSH D02.241.081.844. ...
Both of these substances are degraded to form homovanillic acid (HVA). Both degradations involve the enzymes monoamine oxidase ... 3,4-Dihydroxyphenylacetic acid (DOPAC) is a metabolite of the neurotransmitter dopamine. Dopamine can be metabolized into one ... This product has been synthesized (52% yield) from 4-hydroxyphenylacetic acid via aerobic biotransformation using whole cell ... whereas COMT catalyzes dopamine to 3-MT and MAO catalyzes 3-MT to HVA. The third metabolic end-product of dopamine is ...
3,4-Dihydroxyphenylacetic acid. mg/100 g FW. 1.50. 0.00. 3.00. 2.12. ... Showing details for content value of 3,4-Dihydroxyphenylacetic acid in Olive [Green], raw Food Composition ...
... homovanilic acid. n=9-10 per group. *p,0.05, **p,0.005, ****p,0.00005. Ghrelin-induced changes in nucleus accumbens (e), dorsal ... aromatic L-amino acid decarboxylase); Drd1, dopamine receptor D1; Drd2, dopamine receptor D2; Drd3, dopamine receptor D3; Drd5 ... Figure 3. Ghrelin increases impulsive action measured in the go/no-go task. Centrally injected ghrelin increased the number of ... Figure 4. Ghrelin increases impulsive choice measured in the delay discounting task. Ghrelin treatment increased the amount of ...
Their effects on dialysate dopamine and 3,4-di-hydroxyphenylacetic acid (DOPAC) were measured and compared with the effects of ... Homovanillic Acid / metabolism * Male * Nucleus Accumbens / drug effects * Nucleus Accumbens / metabolism * Raclopride ... Their effects on dialysate dopamine and 3,4-di-hydroxyphenylacetic acid (DOPAC) were measured and compared with the effects of ...
... homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the nucleus accumbens of the rat, prior, during, and after ... homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the nucleus accumbens of the rat, prior, during, and after ... DOI: 10.1016/0166-4328(93)90109-4 Abstract In vivo microdialysis with HPLC-ED was used to measure dopamine (DA), 3,4- ... dihydroxyphenylacetic acid (DOPAC), ...
Abbreviations: 3-methoxytyramine (3MT); 3,4-dihydroxyphenylalanine (L-DOPA); 3,4-Dihydroxyphenylacetic acid (DOPAC); 5-S- ... 4Aligning Science Across Parkinsons (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA ... 3Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain ...
Tyrosine 3-monooxygenase from rat pheochromocytoma.﻽. Tank AW, Weiner N. Methods in enzymology.. 1987 142 :71-82. Epub 1900 01 ... Oxidation of 3,4-dihydroxyphenylacetaldehyde derived from dopamine to 3,4-dihydroxyphenylacetic acid.﻽. Tank AW, Weiner H, ... The Journal of neuroscience : the official journal of the Society for Neuroscience.. 2008 January 1628 (3):672-80. Epub 1900 01 ... cAMP-mediated stimulation of tyrosine hydroxylase mRNA translation is mediated by polypyrimidine-rich sequences within its 3- ...
Our Comprehensive Neurotransmitter Profile includes 19 neurotransmitters and amino acids. ... The neurotransmitters are all produced from essential aromatic amino acids. Neurotransmitter metabolism may be mediated by a ...
Serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic ... acid (HVA) were analyzed via HPLC. Although MDMA-treated monkeys tended to have lower 5-HT concentrations in the frontal cortex ...
Keywords : 3,4-Dihydroxyphenylacetic Acid, alpha-Synuclein, Biomarkers, Brain, Cell death, Computer simulation, Disease ... 5-yr Integrated MSc / 4-yr BSc (Hons) in Physics with a minor in Scientific Computing or Data Science ... Simulations suggest that dopamine levels were reduced significantly due to an increase in dopaminergic quinones and 3,4- ...
2-aminopropanoic acid , CAS Registry Number: 95975-81-8. Synonyms: alpha-Aminotricyclo[3.3.1.13,7]decane-1-propanoic acid, 3- ... a-Amino-cyclobutaneacetic acid tert-butyl ester (2 suppliers). IUPAC Name: tert-butyl 2-amino-2-cyclobutylacetate , CAS ... a-aMino-1-Pyrrolidinebutanoic acid (1 supplier). IUPAC Name: 2-amino-4-pyrrolidin-1-ylbutanoic acid , CAS Registry Number: ... a-Amino-cyclopropaneacetic acid 1,1-dimethylethyl ester (4 suppliers). IUPAC Name: tert-butyl 2-amino-2-cyclopropylacetate , ...
Further, there were no measurable decrements in serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dopamine (DA), 3,4- ... dihydroxyphenylacetic acid (DOPAC) or VMAT in any brain regions assayed. The reinforcing effects of MDMA are selectively ... The effects of self-administered 3,4-methylenedioxymethamphetamine (MDMA) on behavior and neurochemistry have not been ...
5-hydroxyindoleacetic acid, were not significantly different from control values. In contrast to the striatum, MPP+ had no ... 5-hydroxyindoleacetic acid, were not significantly different from control values. In contrast to the striatum, MPP+ had no ... 1-Methyl-4-phenylpyridiniumAnimalsApomorphineCorpus StriatumDopamineDose-Response Relationship, DrugFemaleFunctional Laterality ... Grapherence [↓4]. Related Citations. *Cortical slow oscillatory activity is reflected in the membrane potential and spike ...
NAA concentration was measured by HPLC (L-8500 amino acid analyzer system, Hitachi). The amino acids are phenylalanine, ... A venous blood sample was taken at the beginning of l-[β-11C]DOPA PET scanning for measurement of natural neutral amino acid ( ... 1972) Occurrence and distribution of aromatic L-amino acid (L-DOPA) decarboxylase in the human brain. J Neurochem 19:1549-1559. ... 1977) Kinetics of competitive inhibition of neutral amino acid transport across the blood-brain barrier. J Neurochem 28:103-108 ...
De Souza EB 3,4-Methylenedioxymethamphetamine and 3,4-methylenedioxyamphetamine destroy serotonin terminals in rat brain: ... Marked reductions (30-60%) in the concentration of 5-hydroxyindoleacetic acid were observed in cerebral cortex, hippocampus, ... 1987;242(3):911-6.. Battaglia G, Yeh SY, OHearn E, Molliver ME, Kuhar MJ, De Souza EB. "3,4-Methylenedioxymethamphetamine and ... This study examines the effects of repeated systemic administration (20 mg/kg s.c., twice daily for 4 days) of 3,4- ...
To prepare stearic acid-based lopinavir (LPV) loaded solid lipid nanoparticles (SLNs) using a hybrid design and compare in-vivo ... Modulation of Cytochrome P450 Activity by 18 β -Glycyrrhetic Acid and its Consequence on Buspirone P.... May 2015 · ... The aim of this study was to elucidate the inhibition mechanism of 18β-glycyrrhetic acid (GLY) on cytochrome P450 (CYP) ... steroids and arachidonic acids). Like many of other CYPs, CYP1A2 is subject to induction and inhibition by a number of ...
... abrotanum mainly contained the phenolic acids isochlorogenic acid and rosmarinic acid and the flavonoid quercetin. Leaf ... extracts of both species showed antioxidant activities due to the presence of quercetin, chlorogenic acid, and p-coumaric acid ... R. graveolens mainly contained the phenolic acids chlorogenic acid and p-coumaric acid and the flavonoids rutoside and ... caffeic acid, isochlorogenic acid, and rosmarinic acid and other phenolic acids such as protocatechuic acid, syryngic acid, and ...
... despite the fact that the fish-containing diet was enriched in polyunsaturated fatty acids and selenium compared to the fish- ... and homovanillic acid (HVA) as DA metabolites, and 5-hydroxyindole-acetic acid (5-HIAA) as a 5-HT metabolite were measured. ... 4. .. 6. 4. ±. 0. .. 2. 6. μg/g (mean ± SEM). Our qualification data were 4. .. 5. 1. ±. 0. .. 1. 4. μg/g for total mercury ( ... L. E. Kerper, N. Ballatori, and T. W. Clarkson, "Methylmercury transport across the blood-brain barrier by an amino acid ...
2017). Tauroursodeoxycholic acid protects bile acid homeostasis under inflammatory conditions and dampens Crohns disease-like ... gamma-aminobutyric acid - GABA, and nitric oxide), hormones or neurotoxic metabolites (i.e., D-lactic acid and ammonia) ( ... Synthesized by the gut microbiota from primary bile acids, secondary bile acids bind to their receptors TGR5, FXR and PXR and ... aromatic amino acids and secondary bile acids (Garrett-Bakelman et al., 2019), which are also associated with modulation of the ...
... and homoranillic acid (HVA) in substantial nigra and striatum. The activities of tyrosine hydroxylase (TH) were also detected ... Then HPLC-fluorescence detection was used to analyze the contents of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) ...
... and homovanillic acid (HVA) increased in mouse striatum and limbic forebrain. When dizocilpine was given to animals treated ... General Section 90(3): 199-217. Bespalov, A.; Kudryashova, M.; Zvartau, E. 1998: Prolongation of morphine analgesia by ... General Section 101(1-3): 115-126. Schugens, M.M.; Kaeppeler, E.; Gerhard, N.; Loeschmann, P.A. 1997: Effects of morphine and ... 3-4): 220-226. Tonkiss, J.; Rawlins, J.N. 1991: The competitive NMDA antagonist AP5, but not the non-competitive antagonist ...
5-hydroxyindoleacetic acid, or 5-HIAA), and the serotonin transporter (SERT). Anatomic studies (13) supported these ... R. P. Fink and L. Heimer, Brain Res. 4, 369 (1967) .. 15.. D. B. Calne, R. F. Peppard, Can. J. Neurol. Sci. 14 (suppl. 3), 424 ... 3). Fig. 3. Effect of MDMA treatment on striatal concentrations of (A) dopamine, (B) [3H]WIN35,428-labeled DAT, (C) DOPAC, and ... 4. Silver-stained coronal sections through the caudate nucleus of (A) a control monkey and (B) a monkey treated with MDMA (one ...
Carboxylic Acids [D02.241] * Acids, Carbocyclic [D02.241.223] * Phenylacetates [D02.241.223.601] * Cyclopentolate [D02.241. ... acetic acid.. Terms. Homovanillic Acid Preferred Term Term UI T020286. Date01/01/1999. LexicalTag NON. ThesaurusID ... Homovanillic Acid Preferred Concept UI. M0010524. Registry Number. X77S6GMS36. Related Numbers. 306-08-1. Scope Note. A 3-O- ... Benzeneacetic acid, 4-hydroxy-3-methoxy-. Public MeSH Note. 86; was see under PHENYLACETATES 1975-85. History Note. 86(73); was ...
... and homovanillic acid (HVA), in the medial prefrontal cortex of awake, free-moving rats as measured by in vivo brain ... and homovanillic acid (HVA), in the medial prefrontal cortex of awake, free-moving rats as measured by in vivo brain ... and homovanillic acid (HVA), in the medial prefrontal cortex of awake, free-moving rats as measured by in vivo brain ... and homovanillic acid (HVA), in the medial prefrontal cortex of awake, free-moving rats as measured by in vivo brain ...
4 to 120 ± 3 mmHg, P < 0.05 and heart rate increase from 368 ± 12 to 406 ± 12 BPM, P < 0.05) and had elevated plasma ... 2-4 μg/side) or vehicle treatment at the area surrounding the SCN at 20 min post protriptyline ip injection (20  ... Lam TK, Carpentier A, Lewis GF, van de Werve G, Fantus IG, Giacca A. Mechanisms of the free fatty acid-induced increase in ... In Study 1, rats were subjected to infusion of either 6-OHDA (8 μg/side, N = 8) in saline containing 0.2% ascorbic acid or ...
The weighed striatum was sonicated in 0.1 N perchloric acid, the homogenate was centrifuged at 12,000g for 10 min at 4 °C, and ... Excessive ROS and increased oxidative stress can further attack biomolecules such as proteins, lipids, and nucleic acids in ... proteins and nucleic acids that leads to initiation of death of neurons, serving as a major contributor in PD progression [6]. ... and homovanillic acid (HVA) in the striatum were measured by reverse phase HPLC. MPTP treatment significantly reduced the ...
Mandelic acid. ... of mandelic acid are formed as a result of metabolism of adrenaline and noradrenaline by monoamine oxidase ... Xerocomic acid. An oxidase acting on xerocomic acid is responsible for the "bluing" reaction seen in mushrooms. Condensation of ... It is darker in color than kinotannic acid. ... Chemical Constituents: It contains about 70%- 80% of kino-tannic acid, kino- ... determination of amino acid composition; (b) determination of N-terminal and C-terminal amino acid; (c) determination of sugar ...
p-Hydroxymandelic acid. 1198-84-1. C8H8O4. 168.1467. 168.042258744. commercial. Rosa Vazquez Fresno. [email protected] ... 5-Methoxysalicylic acid. 2612-02-4. C8H8O4. 168.1467. 168.042258744. commercial. Rosa Vazquez Fresno. [email protected] ... Quinolinic acid. 89-00-9. C7H5NO4. 167.1189. 167.021857653. commercial. Rosa Vazquez Fresno. [email protected] ... Phosphoenolpyruvic acid. 138-08-9. C3H5O6P. 168.042. 167.982374404. commercial. Rosa Vazquez Fresno. [email protected] ...
Formula: C8H8O4 KEGG ID: C01161. BiGG ID: 34dhpha. SEED ID: cpd00854 Chebi ID(s): 41941 Pubchem ID(s): 547 ...
  • 3,4-Dihydroxyphenylacetic acid (DOPAC) is a metabolite of the neurotransmitter dopamine. (wikipedia.org)
  • Their effects on dialysate dopamine and 3,4-di-hydroxyphenylacetic acid (DOPAC) were measured and compared with the effects of raclopride. (nih.gov)
  • In vivo microdialysis with HPLC-ED was used to measure dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the nucleus accumbens of the rat, prior, during, and after 15-min periods of electrical brain stimulation at sites in the ventral tegmental area (VTA) that supported intracranial self-stimulation (ICSS). (nih.gov)
  • Serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) were analyzed via HPLC. (erowid.org)
  • Further, there were no measurable decrements in serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) or VMAT in any brain regions assayed. (erowid.org)
  • Then HPLC-fluorescence detection was used to analyze the contents of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homoranillic acid (HVA) in substantial nigra and striatum. (cdc.gov)
  • Following intraperitoneal administration of the non-competitive N-methyl-D-aspartate (NMDA) antagonist dizocilpine (MK-801), levels of the dopamine (DA) metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) increased in mouse striatum and limbic forebrain. (eurekamag.com)
  • Acute clozapine challenge (5-40 mg/kg i.p) produced dose-dependent increased extracellular levels of DA and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), in the medial prefrontal cortex of awake, free-moving rats as measured by in vivo brain microdialysis. (elsevierpure.com)
  • Right hemisphere suction lesions produced a significant bilateral increase in NAS and caudate nucleus dopamine turnover (as measured by DOPAC/DA ratio) 4 weeks post-lesion, while similar left hemisphere lesions did not. (johnshopkins.edu)
  • However, DA metabolites, HVA (homovanillic acid) and DOPAC (3,4-dihydroxyphenylacetic acid) are not responsible for such protection. (uchile.cl)
  • The concentrations of DA and its metabolites including 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in eyes were investigated by HPLC. (atlasofscience.org)
  • The concentrations of norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole acetic acid (5HIAA) in the brain regions were unaffected by the theanine administration except in striatum. (moodfoods.com)
  • We used high-performance liquid chromatography (HPLC) to measure the levels of DA and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the dialysis perfusates. (lu.se)
  • whereas COMT catalyzes dopamine to 3-MT and MAO catalyzes 3-MT to HVA. (wikipedia.org)
  • 1-Methyl-4-phenylpyridinium ion (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, has been chronically infused (10 micrograms/24 h for 7 days) via osmotic minipumps into the left median forebrain bundle of the rat in order to determine whether it can induce permanent damage to the nigrostriatal dopamine system. (unboundmedicine.com)
  • In vivo, using bilateral monitoring of striatal dopamine in MPP+-infused animals at 2 and 4 months by push-pull perfusion, both basal and methamphetamine- (2.5 mg/kg i.p.) stimulated release of dopamine was undetectable in the ipsilateral striatum, indicating a complete loss of dopamine terminals. (unboundmedicine.com)
  • In contrast, in the contralateral striatum of these animals and in striata of saline-infused animals, there were 4-5-fold increases in dopamine release in response to methamphetamine. (unboundmedicine.com)
  • In contrast, neither MDMA nor MDA caused any widespread or long-term changes in the content of the catecholaminergic markers (i.e., norepinephrine, dopamine, 3,4 dihydroxyphenylacetic acid and homovanillic acid) or in the number of [3H]mazindol-labeled norepinephrine or dopamine uptake sites in the brain regions examined. (erowid.org)
  • After two months of feeding, the fish-containing diet resulted in significant observable effects as compared to the control and MeHg-containing diets, encompassing altered behavioral performances as monitored in a Y-shaped maze and an open field, and an increased dopamine metabolic turnover in hippocampus, despite the fact that the fish-containing diet was enriched in polyunsaturated fatty acids and selenium compared to the fish-devoid diets. (hindawi.com)
  • Effect of theanine on brain amino acids and monoamines, and the striatal release of dopamine (DA) was investigated. (moodfoods.com)
  • Another is 3-methoxytyramine (3-MT). Both of these substances are degraded to form homovanillic acid (HVA). (wikipedia.org)
  • This study examines the effects of repeated systemic administration (20 mg/kg s.c., twice daily for 4 days) of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) on levels of brain monoamines, their metabolites and on the density of monoamine uptake sites in various regions of rat brain. (erowid.org)
  • however, the levels of noradrenaline, serotonin and its metabolite, 5-hydroxyindoleacetic acid, were not significantly different from control values. (unboundmedicine.com)
  • The prevailing view is that the popular recreational drug (±)3,4-methylenedioxymethamphetamine (MDMA, or "ecstasy") is a selective serotonin neurotoxin in animals and possibly in humans. (mdma.net)
  • These studies revealed lasting reductions in regional brain serotonin, serotonin's major metabolite (5-hydroxyindoleacetic acid, or 5-HIAA), and the serotonin transporter (SERT). (mdma.net)
  • Low-molecular-weight carboxylic acids are involved in various metabolic pathways. (encyclopedia.pub)
  • Fatty acids are integral components of lipids, and consist of carboxylic acids with long aliphatic chains. (encyclopedia.pub)
  • Hence, highly sensitive and selective methods for the determination of biologically important carboxylic acids are required for biological investigations, and, thus far, numerous analytical methods have been developed. (encyclopedia.pub)
  • The choice of detection method is important for trace amounts of carboxylic acids in biological samples. (encyclopedia.pub)
  • Ultraviolet absorbance detection is rarely implemented due to the absence of chromophores in carboxylic acids. (encyclopedia.pub)
  • A 3-O-methyl ETHER of (3,4-dihydroxyphenyl)acetic acid. (nih.gov)
  • When dizocilpine was given to animals treated with NSD 1015, an inhibitor of 3,4-dihydroxyphenylalanine (DOPA) decarboxylase and monoamine oxidase, there was an increase in levels of DOPA and 3-methoxytyramine (3-MT). These findings suggest that dizocilpine stimulates DA synthesis and release in mouse brain. (eurekamag.com)
  • Determination of amino acids in the brain after the intragastric administration of theanine showed that theanine was incorporated into brain through blood-brain barrier via leucine-preferring transport system. (moodfoods.com)
  • Effects of tyrosine and tryptophan ingestion on plasma catecholamine and 3, 4-dihydroxyphenylacetic acid concentrations. (infinitelabs.com)
  • Scope: (-)-Epicatechin (EC) and main colonic phenolic acids derived from flavonoid intake, such as 2,3-dihydroxybenzoic acid (DHBA), 3,4-dihydroxyphenylacetic acid (DHPAA), 3- hydroxyphenylpropionic acid (HPPA), and vanillic acid (VA), have been suggested to exert beneficial effects in diabetes, although the mechanism for their actions remains unknown. (faksignaling.com)
  • Thus, monomers are readily absorbed in the small intestine, but oligomers and polymers are metabolized in the colon by the intestinal microbiota into different phenolic acids of low molecular weight [7, 9]. (faksignaling.com)
  • The strains demonstrated their biodegradation capacity of oleuropein, associated with the accumulation of hydroxytyrosol and other phenolic compounds, resulting in antioxidant activity values significantly higher than that of ascorbic acid. (springeropen.com)
  • Carboxyl-bearing low-molecular-weight compounds such as keto acids, fatty acids, and other organic acids are involved in a myriad of metabolic pathways owing to their high polarity and solubility in biological fluids. (encyclopedia.pub)
  • The Organic Acids Test (OAT) offers a comprehensive metabolic snapshot of a patient's overall health with 76 markers. (functional-labs.com)
  • Many people with chronic illnesses and neurological disorders often excrete several abnormal organic acids in their urine. (functional-labs.com)
  • Our Organic Acids Test also includes markers for vitamin and mineral levels, oxidative stress, neurotransmitter levels, and is the only OAT to include markers for oxalates, which are highly correlated with many chronic illnesses. (functional-labs.com)
  • The results of cDNA cloning, peptide mapping, and amino acid sequencing of PPAE revealed that PPAE is synthesized as prepro-PPAE with 441 amino acid residues and is activated from pro-PPAE by cleavage of a peptide bond between Lys152 and Ile153. (lookformedical.com)
  • -Tyrosine or tyrosine (symbol Tyr or Y ) [1] or 4-hydroxyphenylalanine is one of the 20 standard amino acid s that are used by cells to synthesize proteins . (explained.today)
  • It is a non-essential amino acid with a polar side group. (explained.today)
  • While tyrosine is generally classified as a hydrophobic amino acid, it is more hydrophilic than phenylalanine . (explained.today)
  • Aside from being a proteinogenic amino acid , tyrosine has a special role by virtue of the phenol functionality. (explained.today)
  • Mammals synthesize tyrosine from the essential amino acid phenylalanine (Phe), which is derived from food. (explained.today)
  • The amino acid tyrosine is a noradrenaline precursor and it may enhance noradrenaline synthesis and release in sympathetic nervous system. (infinitelabs.com)
  • The product, homogentisic acid, is actually ortho-meta- dihydroxyphenylacetic acid. (medscape.com)
  • A deficiency of the hepatic enzyme homogentisate 1,2-dioxygenase (HGO) forces the accumulation of homogentisic acid, which is rapidly cleared in the kidney and excreted. (medscape.com)
  • Upon contact with air, homogentisic acid is oxidized to form a pigmentlike polymeric material responsible for the black color of standing urine. (medscape.com)
  • cAMP-mediated stimulation of tyrosine hydroxylase mRNA translation is mediated by polypyrimidine-rich sequences within its 3'-untranslated region and poly(C)-binding protein 2. (rochester.edu)
  • It varies depending on an estimate method, however the ideal proportion of these two amino acids is considered to be 60:40 (phenylalanine:tyrosine) as a human body has such composition. (explained.today)
  • The thyroid hormones triiodothyronine (T 3 ) and thyroxine (T 4 ) in the colloid of the thyroid are also derived from tyrosine. (explained.today)
  • It transforms L-tyrosine into p-coumaric acid .Tyrosine is also the precursor to the pigment melanin . (explained.today)
  • Tyrosine tended to increase 4-h respiratory quotient by 1% compared to placebo. (infinitelabs.com)
  • Ad libitum energy intake was not significantly different between treatments, but was reduced by 8%, 8%, and 3% compared to placebo after intake of tyrosine, green tea extract and caffeine, respectively. (infinitelabs.com)
  • We found that resveratrol (10 μM) and ascorbic acid (200 μM) protected MeHg-induced cell death in primary cultures of cortical neurons. (uchile.cl)
  • Oxidative stress, induced by enhanced accumulation of intracellular reactive oxygen species (ROS), harmfully affects lipids, proteins and nucleic acids that leads to initiation of death of neurons, serving as a major contributor in PD progression [ 6 ]. (biomedcentral.com)
  • The effects of self-administered 3,4-methylenedioxymethamphetamine (MDMA) on behavior and neurochemistry have not been previously studied in laboratory primates. (erowid.org)
  • In the 1980s, MDMA was generally used on college campuses, with most individuals taking no more than one or two 75- to 150-mg doses, about 1.6 to 2.4 mg per kilogram of body weight (mg/kg), twice monthly ( 3 ). (mdma.net)
  • More recently, MDMA is increasingly used in the context of large, all-night dance parties where partygoers regard the drug as safe and consume multiple doses during the night ( 4 , 5 ). (mdma.net)
  • Squirrel monkeys ( Saimiri sciureus ) were given MDMA at a dosage of 2 mg/kg, three times, at 3-hour intervals, for a total dose of 6 mg/kg ( 13 ). (mdma.net)
  • F ) radioisotope [ 3 H]RTI-55-labeled SERT in coronal section of a control monkey (CON) and a monkey treated with MDMA 2 weeks previously. (mdma.net)
  • In a poorly understood complex reaction, the enzyme phenylpyruvic acid oxidase is thought simultaneously to move the pyruvic acid side chain, to decarboxylate it, and to add an additional hydroxyl group to the ring. (medscape.com)
  • For example, the tricarboxylic acid (TCA) cycle, which is the principal energy-producing process in cells, involves nine carboxylic acid compounds. (encyclopedia.pub)
  • In the phenylpropanoid biosynthesis pathway, the increased expression of 4-coumarate (1.13-fold) and sinapyl alcohol (1.26-fold) triggered by g-C3N4 coexposure with Cd or As played a critical role in promoting plant growth and enhancing rice resistance against metal(loid) stresses. (bvsalud.org)
  • Female Sprague-Dawley rats received either DA neuron neurotoxic lesion by bilateral intra-cannula injection of 6-hydroxydopamine (2-4 μg/side) or vehicle treatment at the area surrounding the SCN at 20 min post protriptyline ip injection (20 mg/kg) to protect against damage to noradrenergic and serotonergic neurons. (biomedcentral.com)
  • Novel therapeutic agents that can protect the dopaminergic neurons, stop or reverse the progression, as well as alleviate motor symptoms are in urgent need for PD patients [ 4 ]. (biomedcentral.com)
  • Substrate specificity of catechol oxidase from Lycopus europaeus and characterization of the bioproducts of enzymic caffeic acid oxidation. (lookformedical.com)
  • The products of enzymic oxidation of caffeic acid were analyzed and isolated by HPLC with diode array detection. (lookformedical.com)
  • The acute thermogenic response was measured in a ventilated hood system for 4 hours following ingestion. (infinitelabs.com)
  • However, the ingested 50 mg caffeine is of rather low dosage compared to previous studies where the acute dose has generally been between 100 and 400 mg caffeine, inducing a thermogenic response between 3 and 16 % compared to the control. (infinitelabs.com)
  • Inasmuch as the suprachiasmatic nuclei (SCN) are the seat of the circadian pacemaker system of the vertebrate body that function via the neuroendocrine axis to synchronize temporal biology (e.g., daily metabolism) with the cyclic environment, it was postulated that such L-DOPA effects were acting at least in part by modulating SCN output function [ 4 ]. (biomedcentral.com)
  • Alkaptonuria, also called black urine disease, alcaptonuria, and black bone disease, is one of 4 disorders originally defined as an inborn error of metabolism by Archibald Garrod in his Croonian Lectures of 1902. (medscape.com)
  • Blood pressure, heart rate (HR), and subjective appetite sensations were assessed hourly and ad libitum energy intake 4-hour post-dose. (infinitelabs.com)
  • doi: 10.1016/0166-4328(93)90109-4. (nih.gov)
  • In this context, a higher faecal excretion and lower tissue accumulation, as well as metallothionein induction in rats following exposure to methylmercury naturally incorporated in fish compared to methylmercury chloride added to the same matrix, have been reported [ 3 ]. (hindawi.com)
  • Male Sprague-Dawley rats received either a right, left or sham frontocortical suction lesion, and were sacrificed 1, 2, and 4 weeks after surgery. (johnshopkins.edu)
  • As Garrod suggested, alkaptonuria is an autosomal recessive genetic trait, although an autosomal dominant transmission pattern in 3 generations in a nonconsanguineous family has been reported. (medscape.com)
  • After 3-5 weeks, MPP+-infused animals showed dose-related ipsilateral and contralateral circling in response to methamphetamine (1-5 mg/kg i.p.) and apomorphine (0.05-0.25 mg/kg s.c.) respectively. (unboundmedicine.com)
  • Results shown represent the mean ± SEM ( n = 3 animals per group). (mdma.net)
  • The competitive NMDA antagonist D-CPPene produced locomotor stimulation as well, but in contrast to following dizocilpine treatment levels of 3-MT decreased. (eurekamag.com)
  • Moreover, the chemical form of methylmercury in fish has been identified as methylmercury-cysteine (MeHg-cysteine), probably as part of larger peptides [ 4 ]. (hindawi.com)
  • In diabetes, there is a marked increase in renal glucose uptake, which might be accompanied by the upregulation of SGLT- 2 and glucose transporter-2 (GLUT-2) levels, and the renal gluconeogenesis is enhanced because of the deregulation of rate-limiting gluconeogenic enzymes [2, 4, 5]. (faksignaling.com)
  • Additionally, defects at the insulin signalling are thought to affect the renal glucose homeostasis and, therefore, to contribute to the hyperglycaemia [4]. (faksignaling.com)
  • T heanine, r-glutamylethylamide, is one of the major components of amino acids in Japanese green tea. (moodfoods.com)