DL-四氢巴马汀对犬心脏血流动力学作用

消旋体四氢巴马汀(dl-tetrahydropalmatine,THP),是从罂栗科紫堇属植物延胡索中提取的一种生物碱,有镇痛、镇静、催眠、舒张平滑肌、降压等作用。近来发现,THP还有广泛的抗心律失常作用,其作用机理相当于Ⅳ类抗心律失常药,为一类似戊脉安的钙通道阻滞剂。本文观察了THP对麻醉开胸犬的血流动力学作用,为探索THP的作用机理及今后临床用药提供一定的参考。

EFFECTS OF dl-TETRAHYDROPALMATINE ON CARDIAC HEMODYNAMICS IN DOGS

The two-way effects of dl-tetrahydropalmatine (THP) on cardiac hemodynamics were examined in 8 anesthetized open-chest dogs. Intravenous injection of THP (5 or 15 mg/kg) produced a dose-dependent positive inotropic effect rapidly. The left ventricular systolic pressure (LVSP), maximal rate of change of intraventricular pressure (dp/dt_(max)) and cardiac index (CI) were increased significantly, then decreased rapidly. Systolic blood pressure (SBP), diastolic blood pressure (DBP), V_(CE) at dp/dt_(max) (V_(CE)-dp/dt_(max)) and total peripheral resistance (TPR) were decreased. The time constant of isovolumic diastolic pressure decay (T_(value)) was increased after drug administration. When marked depression of cardiac contractility appeared after drug administration, CI decreased slightly.