Possible alpha-adrenoceptor blocking activity of arotinolol (S-596), a new beta-adrenoceptor blocking agent in isolated dog coronary artery.
Effects of arotinolol on dog coronary arteries were investigated in vitro. In distal portions of left circumflex coronary arteries contracted with 3 X 10(-2)M KCl, norephinephrine relaxed the strips in a concentration-dependent fashion. Propranolol (10(-6)M) converted the norepinephrine-induced relaxations to contractions, and arotinolol (10(-6)-10(-5)M) inhibited the relaxations induced by norepinephrine in a concentration-dependent manner. In proximal portions of the strips after potassium-contracture, norephinephrine produced concentration-dependent contractions which were augmented by propranolol (10(-6)M) and inhibited by arotinolol (10(-6)-10(-5)M). These results suggest that arotinolol has an alpha-adrenoceptor blocking activity in addition to a beta-adrenoceptor blocking action in dog coronary arteries.
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C024523:arotinolol; D011433:Propranolol; D009638:Norepinephrine; D010646:Phentolamine