Comparison of the alpha-adrenoceptor profiles of clonidine and two oxygenated arylamino imidazolines.
The profiles of 2-(3,4-dimethoxyphenylamino)-imidazoline HCl (RX 77171) and 2-[6-(1,4-benzodioxanylamino)]imidazoline maleate (RX 801074) were compared with that of clonidine in isolated tissues and pithed rats. RX 77171 consistently displayed prejunctional alpha 2-adrenoceptor antagonist and postjunctional agonist properties. In contrast, RX 801074 had a complex profile which showed considerable variability between tissues. This variability is highlighted by comparing its effects at the prejunctional alpha 2-adrenoceptors of the isolated vas deferens and guinea-pig ileum; in the former RX 801074 was an agonist whereas only antagonist properties were apparent in the ileum.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004558:Electric Stimulation; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D014649:Vas Deferens / Q000187:drug effects
D011942:Receptors, Adrenergic, alpha; C039190:2-(6-(1,4-benzodioxanyl)amino)imidazoline maleate; C039189:2-(3,4-dimethoxyphenylamino)imidazoline; D003000:Clonidine