Dopamin

BeschreibungDopamine, abbreviated DA, is a biosynthetic compound and neurotransmitter produced in the body from the amino acid tyrosine by several pathways. It is synthesized in the adrenal gland where it is a precursor to other hormones (see Epinephrine) and in several portions of the brain, principally the substantia nigra and hypothalamus.

HistoryDopamine is stored in vesicles in the brain’s presynaptic nerve terminals. It is closely associated with its immediate precursor, l-Dopa (levodopa). Casmir Funk (1884–1967) first synthesized Dopa in racemic form in 1911 and considered Dopa a vitamin. In 1913, Marcus Guggenheim, a biochemist from Hoff man-LaRoche, isolated l-Dopa from seedlings of Vicia faba, the Windsor bean plant native to northern Africa and southwest Asia. Guggenheim used beans from the garden of Felix Hoff man (1868–1946), the discoverer of aspirin. Guggenheim ingested a 2.5-gram dose of l-Dopa, resulting in nausea and vomiting; he also administered small dosages to animals and did not observe any signifi cant effects. This led him to believe that l-Dopa was biologically inactive. Studies commencing in 1927 reported that Dopa played a role in glucose metabolism and aff ected arterial blood pressure. Interest in dopamine accelerated in 1938 when the German physician and pharmacologist Peter Holtz (1902–1970) and co-workers discovered the enzyme l-Dopa decarboxylase and that it converted l-Dopa into dopamine in humans and animals. Research over the next two decades focused on l-Dopa’s role as a precursor to other catecholamine hormones, its vascular effects, and its role in brain chemistry.

VerwendenDopamine(3-Hydroxytyramine) is used as a drug to treat several conditions. It can be injected as a solution ofdopamine hydrochloride, such as in the drug Intropin. It is used as a stimulant to the heartmuscle to treat heart conditions; it also constricts the blood vessels, increasing systolic bloodpressure and improving blood flow through the body. Dopamine is used in renal medicationsto improve kidney function and urination. Dopamine dilates blood vessels in the kidneys,increasing the blood supply and promoting the fl ushing of wastes from the body. Dopamineis used to treat psychological disorders such as schizophrenia and paranoia.