Department of Physiology, Basic Medical College, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
J Ethnopharmacol. 2012 Feb 15;139(3):746-50. doi: 10.1016/j.jep.2011.11.054. Epub 2011 Dec 17.
This work aims to investigate the effects of HSYA on cardiac function and blood pressure.
To evaluate changes in mean arterial pressure (MAP) and heart rate (HR), different groups of pentobarbitone-anesthetized normotensive and spontaneously hypertensive rats (SHR) were treated with intravenous HSYA (0.1-3 mg/kg). Isolated WKY rat hearts in Langendorff system were employed for examining the effect of HSYA on hemodynamic. After 30 min equilibration time the isolated hearts were perfused with HSYA (30 μmol/L) in a stepwise fashion. Potassium channel inhibitors were used to determine the role of potassium channel activation in HSYA effect.
Intravenous injection of the HSYA significantly reduced MAP and HR in both normotensive rats and SHR in a dose-dependent manner. HSYA reduced left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of increase of left ventricular pressure (+dp/dt(max)) and heart rate (HR) in a dose-dependent manner. HSYA had no remarkable effect on the maximum rate of decrease of left ventricular pressure (-dp/dt(max)); BK(Ca) and K(ATP) blocker can weakened the inhibitory effect of HSYA on heart function and HR, but K(V) and K(ACh) blocker did not significantly weaken the HSYA effects.
Our results show that HSYA could significantly reduce blood pressure and heart rate, which may be related to activation of BK(Ca) and K(ATP) channels.
本研究旨在探讨 HSYA 对心功能和血压的影响。
为评估平均动脉压（MAP）和心率（HR）的变化，用静脉注射 HSYA（0.1-3mg/kg）对戊巴比妥钠麻醉的正常血压大鼠和自发性高血压大鼠（SHR）的不同组进行处理。采用 Langendorff 系统分离 WKY 大鼠心脏，观察 HSYA 对血流动力学的影响。在 30min 的平衡时间后，用 HSYA（30μmol/L）逐步灌流分离心脏。使用钾通道抑制剂来确定钾通道激活在 HSYA 效应中的作用。
静脉注射 HSYA 可显著降低正常血压大鼠和 SHR 的 MAP 和 HR，呈剂量依赖性。HSYA 呈剂量依赖性降低左心室收缩压（LVSP）、左心室舒张末期压（LVEDP）、左心室压力最大上升速率（+dp/dt（max））和心率（HR）。HSYA 对左心室压力最大下降速率（-dp/dt（max））没有显著影响；BK（Ca）和 K（ATP）通道阻滞剂可减弱 HSYA 对心功能和 HR 的抑制作用，但 K（V）和 K（ACh）通道阻滞剂对 HSYA 作用无明显减弱。
我们的研究结果表明，HSYA 可显著降低血压和心率，这可能与 BK（Ca）和 K（ATP）通道的激活有关。
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