[The influence of treatment with cocaine on the synthesis and liberation of cerebral noradrenaline].
The influence of cocaine (10 mg/kg, i.m.) on the synthesis and the release of noradrenaline (NA) has been studied in rat brain. Cocaine pretreatment reduced significantly the amount of NA-3H synthetized from tyrosine-3H (TY-3H) in the whole brain and various cerebral structures. The synthesis rates of NA (estimated by calculation of the ratio: amount of NA-3H/tissular specific activity of TY-3H) were reduced by 40% in the whole brain, 30 and 60 min after administration of TY-3H. The rise of the NA endogenous level 10 min after administration of a monamine  oxidase inhibitor (ranylcypromine) was inhibited after cocaine treatment. The release of NA has been studied after inhibition of its synthesis by alpha-methyl-paratyrosine. Cocaine pretreatment significantly delayed the disappearance rate of cerebral NA. The possible mechanisms by which cocaine reduced NA turnover are discussed.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D001923:Brain Chemistry / Q000187:drug effects; D003042:Cocaine / Q000494:pharmacology*; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology; D009638:Norepinephrine / Q000096:biosynthesis / Q000378:metabolism*; D051381:Rats; D014191:Tranylcypromine / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
D008781:Methyltyrosines; D014191:Tranylcypromine; D014443:Tyrosine; D003042:Cocaine; D009638:Norepinephrine
Influence du traitement par la cocaïne sur la synthèse et la libération de la noradrénaline cérébrale