[Selective stimulation of histamine H3 autoreceptors].
A simple derivative of histamine, alpha-methylhistamine i.e. 4-(2-aminopropyl)-imidazole, was shown to potently inhibit the K+-induced release of [3H] histamine from slices of rat cerebral cortex previously incubated in the presence of [3H] histidine. The maximal inhibition elicited by alpha-methylhistamine was of about 60% i.e. similar to that elicited by exogenous histamine. The effect occurred with an EC50 value of 4.3 +/- 1.1 X 10(-9) M about 10 times lower than that of histamine and was reversed by a H3-receptor antagonist. Since alpha-methylhistamine is known to display negligible potency at H1- and H2-receptors, this compound appears to be the first highly potent and selective H3-receptor agonist to be identified.
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism; D006633:Histamine Antagonists / Q000032:analysis; D008297:Male; D008761:Methylhistamines / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D011968:Receptors, Histamine / Q000187:drug effects*; D018100:Receptors, Histamine H3
D006633:Histamine Antagonists; D008761:Methylhistamines; D011968:Receptors, Histamine; D018100:Receptors, Histamine H3
Stimulation sélective des autorécepteurs H3 de l'histamine.