Studies on the sympathomimetic effects of guanoxan on smooth muscles of rat.
In anococcygeus muscle and vas deferens preparations of rat, guanidinomethyl-2-benzo-(1,4)-dioxane (guanoxan) potentiated responses to norepinephrine (NF) in concentrations which exerted a neurone blocking effect. The potentiation was significantly reduced in reserpinized preparations and was abolished in the presence of nialamide. The possible mechanisms of potentiation have been discussed. Higher concentrations of guanoxan produced concentration-related contractions. The contractions were significantly less in reserpinized preparations. Phentolamine both prevented and reversed the contractions while methysergide was ineffective in this respect. Thus the effect of guanoxan appears to be mediated through the activation of alpha-receptors by the released NE.
D000818:Animals; D004357:Drug Synergism; D006146:Guanidines / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D013565:Sympatholytics; D013566:Sympathomimetics
D006146:Guanidines; D013565:Sympatholytics; D013566:Sympathomimetics; D009638:Norepinephrine