Cardiovascular effects of the novel potassium channel opener bimakalim in conscious pigs after myocardial infarction: A comparative study with nicorandil

摘要

The benzopyran-derivative bimakalim is an ATP-dependent potassium channel activator that has been shown to be a potent arterial vasodilator in anesthetized pigs. In the present study we evaluated the cardiovascular profile of bimakalim in normal concious animals and concious animals with chronic left ventricular dysfunction and compared the results to those obtained with nicorandil. In normal conscious pigs, bimakalim (37.5–300 ng/kg/min, n=6) and nicorandil (10–80 μg/kg/min, n=8) increased cardiac output from 2.7±0.1 l/min to 3.8±0.2 l/min and from 2.7±0.1 l/ min to 3.9±0.3 l/min (both p<.05) due to increases in heart rate (up to 62±14 and 74±9, respectively, both p<.05). The mean arterial blood pressure decreased gradually from 104±4 mmHg to 91±5 mmHg with bimakalim and from 98 ±3 mmHg to 84±5 mmHg with nicorandil (both p<.05), due to similar decreases in systemic vascular resistance. LVdP/dtmaxalso increased with both drugs (up to 48±11 and 69±7, respectively, p<.05), but left ventricular end-diastolic pressure remained unchanged with bimakalim, while it gradually decreased from 9±1 mmHg to 5±1 mmHg (p<.0