Effect of 2-Nicotinamidethyl Nitrate (SG 75) on Coronary Circulation

抄録

The effect of a new chemical agent, SG 75, on coronary blood flow of anesthetized dogs has been examined. Intravenous administrations of this agent in a dose of 10μg/Kg or over caused a significant increase in blood flow of non-constricted coronary artery. Percent increases in flow were 40 (10μg/Kg), 95 (50μg/Kg), 145 (100μg/Kg), and 195 (250μg/Kg). The increases were significantly larger than those caused by the same doses of diltiazem, verapamil, nitroglycerin, isosolbide dinitrate, and papaverine. The durations of the increase in flow were 12 (10μg/Kg), 23 (50μg/Kg), 28 (100μg/Kg), and 46 min (250μg/Kg), and they were longer than those caused by diltiazem and verapamil. A slight reduction in left ventricular tension and an increase in aortic blood flow were also observed following the administrations of SG 75 in a dose of over 50μg/Kg. A decrease in heart rate was produced with a dose of over 500μg/Kg. However, PQ interval of electrocardiogram became shorter. Intravenous administrations of SG 75 in doses of 50 and 150μg/Kg caused an increase in blood flow of the constricted coronary artery, while nitroglycerin (10 and 30μg/Kg) and nifedipine (1 and 3μg/Kg) reduced it. The results indicate that SG 75 is a potent and long-acting coronary vasodilating agent and it causes an increase in blood flow of constricted as well as non-constricted coronary artery.