Influence of the H2-receptor blocking agent metiamide on the clonidine-induced changes in the brain catecholamine turnover.
Metiamide (800 micrograms intracerebroventricularly to rats) enhanced the DOPA accumulation in noradrenaline-predominant brain areas following DOPA decarboxylase inhibition and it accelerated the alpha-methyltyrosine-induced disappearance of noradrenaline in the brain, both normally and after clonidine (0.1 mg/kg i.p.). These findings indicate that metiamide stimulates the release of noradrenaline. They can explain why metiamide antagonizes the clonidine-induced hypotension.
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D003000:Clonidine / Q000494:pharmacology*; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology; D008785:Metiamide / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011968:Receptors, Histamine / Q000187:drug effects*; D011970:Receptors, Histamine H2 / Q000187:drug effects*; D013890:Thiourea / Q000031:analogs & derivatives*
D008781:Methyltyrosines; D011968:Receptors, Histamine; D011970:Receptors, Histamine H2; D008785:Metiamide; D004295:Dihydroxyphenylalanine; D013890:Thiourea; D003000:Clonidine; D004298:Dopamine; D009638:Norepinephrine