Tsuboi M, Chiba S
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
Heart Vessels. 1999;14(6):289-94. doi: 10.1007/BF03257241.
Direct inotropic effects of lidocaine on ventricular muscle were investigated in isolated canine left ventricular preparations which were perfused with a donor dog's arterial blood. Intravenous administration of lidocaine in doses of less than 1 mg/kg did not cause any significant hemodynamic or cardiac changes in the donor dog and in the isolated ventricular preparation. A large dose of 10mg/kg of lidocaine produced a marked depressor response in the donor and a negative inotropic effect in the isolated ventricle. Direct injection of lidocaine (1-30 micromol) to the isolated preparation induced a dose-related decrease in the ventricular contractile force. Infusion of lidocaine (3 micromol/ml per min) did not influence norepinephrine- or calcium chloride-induced positive inotropic effects. In the frequency-force relationship, lidocaine generally depressed the contractility, exhibiting the positive staircase phenomenon. On the other hand, a calcium entry inhibitor, diltiazem, readily caused the negative staircase. From these results, it is concluded that (1) a large amount of lidocaine has a cardiac depressant property, (2) lidocaine has no antiadrenergic properties, and (3) the action of lidocaine may probably be due to the effect of intracellular calcium movement but not to a modification of Ca inward currents.
在使用供体犬动脉血灌注的离体犬左心室标本中，研究了利多卡因对心室肌的直接变力作用。静脉注射剂量小于1mg/kg的利多卡因，对供体犬和离体心室标本均未引起任何显著的血流动力学或心脏变化。大剂量10mg/kg的利多卡因在供体中产生明显的降压反应，在离体心室中产生负性变力作用。向离体标本直接注射利多卡因（1 - 30微摩尔）可引起与剂量相关的心室收缩力下降。输注利多卡因（每分钟3微摩尔/毫升）不影响去甲肾上腺素或氯化钙诱导的正性变力作用。在频率 - 力关系中，利多卡因通常会降低收缩性，表现出正阶梯现象。另一方面，钙内流抑制剂地尔硫卓很容易引起负阶梯现象。从这些结果可以得出结论：（1）大量利多卡因具有心脏抑制特性；（2）利多卡因没有抗肾上腺素能特性；（3）利多卡因的作用可能是由于细胞内钙运动的影响，而不是对钙内向电流的改变。
