Dopamine
Dopamine is "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 (dopamine receptors) mediate its action."[1]
Dopamine regulates the secretion of prolactin from the anterior pituitary gland. Dopamine is released from specialised neurons of the arcuate nucleus of the hypothalamus into the blood vessels of the median eminence, which transport the dopamine to the pituitary gland where it inhibits prolactin secretion from lactotroph cells.
Dopamine receptors
D1-like receptors
These receptors stimulate adenylate cyclase.[2]
- D1 receptors
- D5 receptors
D2-like receptors
These receptors inhibit adenylate cyclase.[3]
- Dopamine D2 receptors
Agonists, such as metoclopramide, are used as antiemetics.
Antagonists, such as risperidone and haloperidol, are used to treat schizophrenia.[4]
Blockade of the D2 receptors, which may be predisposed by genetic polymorphisms of the allele, may cause neuroleptic malignant syndrome.[5]
- D3 receptors
Agonists of D3, especially nonergot agonists such as pramipexole and ropinirole, may be used to treat Parkinonism and restless legs syndrome.[6]
- D4 receptors
References
- ↑ Anonymous (2024), Dopamine (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Anonymous (2024), Receptors, Dopamine D1 (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Anonymous (2024), Receptors, Dopamine D2 (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Katzung, Bertram G. (2001). Basic & clinical pharmacology. New York: Lange Medical Books/McGraw-Hill, 483. ISBN 0-8385-0598-8.
- ↑ Kishida I, Kawanishi C, Furuno T, Kato D, Ishigami T, Kosaka K (2004). "Association in Japanese patients between neuroleptic malignant syndrome and functional polymorphisms of the dopamine D(2) receptor gene". Mol. Psychiatry 9 (3): 293-8. DOI:10.1038/sj.mp.4001422. PMID 15094790. Research Blogging.
- ↑ Baker WL, White CM, Coleman CI (2008). "Effect of nonergot dopamine agonists on symptoms of restless legs syndrome". Ann Fam Med 6 (3): 253–62. DOI:10.1370/afm.845. PMID 18474889. Research Blogging.