Preuss K C, Brooks H L, Gross G J, Warltier D C
Basic Res Cardiol. 1985 May-Jun;80(3):326-32. doi: 10.1007/BF01907908.
The hemodynamic effects of the dihydropyridine derivative Bay k 8644, a new calcium agonist with positive inotropic actions, were studied in instrumented conscious dogs before and after beta adrenergic blockade with propranolol. Intravenous Bay k 8644 (2, 4, 8 and 20 micrograms/kg/min) produced dose-related increases in arterial and left ventricular systolic pressures and myocardial contractility (+dP/dt; % segment shortening). Coronary blood flow velocity was increased at higher doses. Prior administration of propranolol produced no significant alteration of the hemodynamic effects of Bay k 8644. Increases in arterial and left ventricular pressures produced by Bay k 8644 were controlled by intravenous infusion of sodium nitroprusside with resulting enhancement of positive inotropic effects. The results demonstrate that the hemodynamic responses to this novel calcium agonist with positive inotropic properties are not mediated via beta adrenergic mechanisms and control of increases in arterial pressure lead to enhanced regional contractility.
研究了新型具有正性肌力作用的钙激动剂二氢吡啶衍生物Bay k 8644在用普萘洛尔进行β肾上腺素能阻断前后，对麻醉清醒犬的血流动力学效应。静脉注射Bay k 8644（2、4、8和20微克/千克/分钟）可使动脉压和左心室收缩压以及心肌收缩力（+dP/dt；节段缩短百分比）呈剂量依赖性增加。高剂量时冠状动脉血流速度增加。预先给予普萘洛尔对Bay k 8644的血流动力学效应无显著改变。静脉输注硝普钠可控制Bay k 8644引起的动脉压和左心室压力升高，并增强正性肌力作用。结果表明，对这种具有正性肌力特性的新型钙激动剂的血流动力学反应不是通过β肾上腺素能机制介导的，控制动脉压升高可增强局部收缩力。
