多巴酚丁胺对大鼠心室肌细胞Na^+/Ca^(2+)交换的影响及其受体机制

Effect of dobutamine on Na^+/Ca^(2+) exchange and the involved receptor mechanisms in ventricular myocytes of rat

目的 观察多巴酚丁胺对大鼠心室肌细胞Na+ /Ca2 + 交换电流的作用及其肾上腺素能受体机制。方法 用胶原酶消化的成年大鼠心室肌单个细胞及全细胞膜片钳技术 ,记录Na+ /Ca2 + 交换电流并观察药物对它的作用。结果 多巴酚丁胺呈剂量依赖性地增加大鼠心室肌细胞Na+ /Ca2 +交换电流 ,该作用可分别被 β和 β1受体阻断剂普萘洛尔和美托洛尔阻断。结论 多巴酚丁胺通过β1 受体途径增加大鼠心室肌细胞Na+ /Ca2 + 交换电流 ,这可能是多巴酚丁胺正性变力作用的一个新的机制。

Objective To investigate the effect of dobutamine on Na +/Ca 2+ exchange current and the involved adrenoceptor mechanisms in ventricular myocytes of rat Methods Whole cell patch clamp technique was used to record the Na +/Ca 2+ exchange current and to observe its alteration induced by drugs Results Dobutamine increased the Na +/Ca 2+ exchange current with a dose dependent manner in ventricular myocytes of rat and this effect could be blocked by propranolol and metoprolol, respectively Conclusion The effect of dobutamine on Na +/Ca 2+ exchange current is mediated by β 1 receptor, and this effect may be a new mechanism underlying the positive inotropic action of dobutamine