Effect of disopyramide on isolated aortic ring of the rat.
Disopyramide produces a contraction of the isolated aortic ring of the rat which is graded, develops slowly, and has a time course similar to the tonic phase of the noradrenaline response. This effect is not modified by alpha-adrenoceptor blockade (yohimbine) but is completely abolished by a Ca2+ antagonist (verapamil) or by removal of Ca2+ from the bathing solution. These results indicate that, in the rat aorta, disopyramide has a vasoconstrictor effect dependent on Ca2+ influx across the vascular smooth muscle membrane.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects; D002118:Calcium / Q000502:physiology; D004206:Disopyramide / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D011725:Pyridines; D014700:Verapamil; D004206:Disopyramide; D002118:Calcium; D009638:Norepinephrine