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. [PubChem]
Indication
For the correction of hemodynamic imbalances present in the shock syndrome due to myocardial infarction, trauma, endotoxic septicemia, open-heart surgery, renal failure, and chronic cardiac decompensation as in congestive failure
Pharmacology
Dopamine is a natural catecholamine formed by the decarboxylation of 3,4-dihydroxyphenylalanine (DOPA). It is a precursor to norepinephrine in noradrenergic nerves and is also a neurotransmitter in certain areas of the central nervous system, especially in the nigrostriatal tract, and in a few peripheral sympathetic nerves. Dopamine produces positive chronotropic and inotropic effects on the myocardium, resulting in increased heart rate and cardiac contractility. This is accomplished directly by exerting an agonist action on beta-adrenoceptors and indirectly by causing release of norepinephrine from storage sites in sympathetic nerve endings.
Toxicity
LD50 oral mice = 1460 mg/kg, LD50 oral rats = 1780 mg/kg. Spasm or closing of eyelids, nausea, vomiting, cardiac arrhythmias, involuntary movements of the body including the face, tongue, arms, hand, head, and upper body; hypotension, haemolytic anaemia, urinary retention, duodenal ulcer, sialorrhea, ataxia, abdominal pain, dry mouth, nightmares, tachypnoea, bruxism, confusion, and insomnia.
Affected Organisms
Humans and other mammals
Biotransformation
Biotransformation of dopamine proceeds rapidly to yield the principal excretion products, 3-4-dihydroxy-phenylacetic acid (DOPAC) and 3-methoxy-4-hydroxy-phenylacetic acid (homovanillic acid, HVA).
Absorption
Dopamine is rapidly absorbed from the small intestine.
Half Life
2 minutes
Protein Binding
No information currently available on protein binding.
Elimination
It has been reported that about 80% of the drug is excreted in the urine within 24 hours, primarily as HVA and its sulfate and glucuronide conjugates and as 3,4-dihydroxyphenylacetic acid. A very small portion is excreted unchanged.
References
•
Barron AB, Maleszka R, Vander Meer RK, Robinson GE: Octopamine modulates honey bee dance behavior. Proc Natl Acad Sci U S A. 2007 Jan 30;104(5):1703-7. Epub 2007 Jan 19.
[Pubmed]
•
Giuliano F, Allard J: Dopamine and male sexual function. Eur Urol. 2001 Dec;40(6):601-8.
[Pubmed]
•
Giuliano F, Allard J: Dopamine and sexual function. Int J Impot Res. 2001 Aug;13 Suppl 3:S18-28.
[Pubmed]
•
Berridge KC, Robinson TE: What is the role of dopamine in reward: hedonic impact, reward learning, or incentive salience? Brain Res Brain Res Rev. 1998 Dec;28(3):309-69.
[Pubmed]
•
Pecina S, Cagniard B, Berridge KC, Aldridge JW, Zhuang X: Hyperdopaminergic mutant mice have higher "wanting" but not "liking" for sweet rewards. J Neurosci. 2003 Oct 15;23(28):9395-402.
[Pubmed]
Catechol in which the hydrogen at position 4 is substituted by a 2-aminoethyl group.
References
PubChem Literature
From Data Sources
• Giuliano F, Allard J: Dopamine and sexual function. Int J Impot Res. 2001 Aug;13 Suppl 3:S18-28. Pubmed
• Pecina S, Cagniard B, Berridge KC, Aldridge JW, Zhuang X: Hyperdopaminergic mutant mice have higher "wanting" but not "liking" for sweet rewards. J Neurosci. 2003 Oct 15;23(28):9395-402. Pubmed
• Giuliano F, Allard J: Dopamine and male sexual function. Eur Urol. 2001 Dec;40(6):601-8. Pubmed
• Berridge KC, Robinson TE: What is the role of dopamine in reward: hedonic impact, reward learning, or incentive salience? Brain Res Brain Res Rev. 1998 Dec;28(3):309-69. Pubmed
• Barron AB, Maleszka R, Vander Meer RK, Robinson GE: Octopamine modulates honey bee dance behavior. Proc Natl Acad Sci U S A. 2007 Jan 30;104(5):1703-7. Epub 2007 Jan 19. Pubmed
