Direct evidence for brain-specific release of dopamine from a redox delivery system.
Dopamine (1) was transformed into a lipoidal redox chemical delivery system which crosses the blood brain barrier and is converted to a quaternary ammonium precursor of 1, thus "locking in" this ionized moiety. Systemic administration of this chemical delivery system for 1 increased concentrations of the major acid metabolite of 1, dihydroxyphenylacetic acid, (6) in several brain regions, and despite sustained inhibition of prolactin secretion, concentrations of 1 were unchanged. Inhibition of monoamine oxidase did not encourage the formation of 1 from this delivery system. When de novo synthesis of 1 was inhibited, however, regional brain concentrations of both 1 and dihydroxyphenylacetic acid acid were increased by systemic administration of the delivery system. This study provides direct evidence for the brain-specific delivery of 1 by a redox chemical delivery system and indicates that the 1 formed is delivered to sites which normally store newly biosynthesized 1.
D000818:Animals; D001921:Brain / Q000201:enzymology / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism* / Q000494:pharmacology; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D010084:Oxidation-Reduction; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D013239:Stereotyped Behavior / Q000187:drug effects; D013997:Time Factors
D011388:Prolactin; D008995:Monoamine Oxidase; D004298:Dopamine