title: Effects of a new beta-adrenoceptor blocking agent, S-596 (arotinolol), on isolated dog coronary arteries.
abstract: Effects of S-596 on dog coronary arteries were investigated in vitro. S-596 produced concentration-dependent relaxations of coronary arterial strips under potassium-, prostaglandin (PG) F2 alpha- or PGE2-contracture. S-596-induced relaxations of the strips were not influenced by tetraethylammonium or tranylcypromine, but restored by additional Ca++ or prevented by prior administration of Ca++. In distal portions of coronary arteries, S-596 significantly inhibited concentration-dependent relaxations of the strips induced by norepinephrine and reversed to weak contractions. In proximal portions, S-596 significantly inhibited concentration-dependent contractions induced by norepinephrine. Results indicate that S-596 has a nonspecific relaxant effect on isolated dog coronary arteries maybe through impairment of Ca++ availability and simultaneously has an alpha-adrenoceptor blocking effect, particularly on large coronary arteries.
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D015237:Dinoprost; D015232:Dinoprostone; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D011458:Prostaglandins E / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011458:Prostaglandins E; D011460:Prostaglandins F; D011942:Receptors, Adrenergic, alpha; C024523:arotinolol; D011433:Propranolol; D015237:Dinoprost; D015232:Dinoprostone; D011188:Potassium; D009638:Norepinephrine