Action of stereoisomers of (imidazolinyl-2)-2-benzodioxane-1-4 or 2-(2-(1,4-benzodioxanyl))-2-imidazoline (170 150; RX 781094) on peripheral presynaptic and central alpha 2-adrenoceptors.
In the vas deferens of the rat, (-)-170 150 (imidazolinyl-2)-benzodioxane-1-4 or 2-(2-(1,4-benzodioxanyl))-2-imidazoline appeared to be more selective than (+)-170 150 for antagonizing the inhibitory effects of clonidine on the twitch response. In contrast, (+)-170 150 was the most potent of the two isomers for antagonizing the centrally mediated clonidine- or azepexole-induced sleep in chickens. These unexpected results seem to indicate that there are several subpopulations of alpha 2-adrenoceptors.
D000818:Animals; D001921:Brain / Q000187:drug effects; D002645:Chickens; D003000:Clonidine / Q000494:pharmacology; D004147:Dioxins / Q000494:pharmacology*; D004558:Electric Stimulation; D019329:Idazoxan; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010525:Peripheral Nerves / Q000187:drug effects; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects* / Q000378:metabolism; D012890:Sleep / Q000187:drug effects; D013237:Stereoisomerism; D014649:Vas Deferens / Q000187:drug effects
D004147:Dioxins; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D003000:Clonidine; D019329:Idazoxan