Effects of
OP 1206 were studied on the cardiovascular system and platelet functions to assess
OP 1206 as an antianginal agent.
OP 1206 given orally at more than 100 micrograms/kg relieved
vasopressin-induced ST depression of rat electrocardiogram (ECG), an animal model of
angina pectoris, concomitant with slight
hypotension. Intra-coronary injection of
OP 1206 (1-100 ng/kg) in dogs resulted in a remarkable increase of coronary blood flow without any influence on heart rate, blood pressure, myocardial oxygen consumption and redox potential. Resistance in both large and small vessels of dog coronary artery was decreased by
intravenous injection of
OP 1206 (1-3 micrograms/kg). Platelet aggregation, adhesiveness, bleeding time, and
thrombocytopenia induced by
ADP and
collagen infusion in guinea-pigs were inhibited by
oral administration of
OP 1206 at the same doses or doses less than those relieving
vasopressin-induced ST depression of ECG. These results suggest that
OP 1206 contributes to the improvement of cardiac imbalance between
oxygen demand and supply, and suppression of
thrombus formation in atherosclerotic heart.