双龙方对离体大鼠冠状动脉舒缩功能的影响及机制

Effect of Shuanglong Formular on the Relaxation and Contractile Function of the Isolated Coronary Artery in Rats and Its Mechanism

目的探讨双龙方对大鼠离体冠状动脉舒缩功能的影响及其作用机制。方法应用离体微血管动力描记技术和离子通道特异性阻断方法,考察双龙方对大鼠冠状动脉环的直接舒张作用,及其对电压依赖型、受体依赖型钙通道功能的影响。结果双龙方低、中、高质量浓度组(相当于每1 L含8,16,32 g生药)大鼠冠状动脉均显著舒张,其舒张率与空白对照组比较,均有显著差异(P<0.01)。与空白对照组比较,双龙方高质量浓度组(相当于每1 L含8 g生药)氯化钾最大收缩达5-羟色胺(5-HT)预收缩高度(Emax)显著降低(P<0.05),双龙方高、中、低质量浓度组(相当于每1 L含8,4,2 g生药)中5-HT的Emax均显著降低(P<0.01),双龙方高、中质量浓度组(相当于每1 L含8,4 g生药)中血栓素A2受体激动剂(U46619)的Emax均显著降低(P<0.01)。结论双龙方可显著扩张血管,其作用机制与抑制电压依赖型钙离子通道开放及5-HT、血栓素A2受体激活有关。

Objective To investigate the effect of Shuanglong Formular on the relaxation and contraction function of isolated coronary artery in rats and its mechanism.Methods The direct relaxation effect of Shuanglong Formular on rat coronary artery rings and its effect on the function of voltage-dependent and receptor-dependent calcium channels were investigated by using in vitro microvascular dynamic tracing technique and ion channel specific blocking method.Results Shuanglong Formular low,medium and high concentration groups(equivalent to 8,16,32 g crude drug/L)could significantly relax the coronary artery in rats,and their relaxation rates were significantly different from that in the blank control group(P<0.01).The maximum contraction of KCl in Shuanglong Fang high concentration group(equivalent to 8 g crude drug/L)reached the pre-contraction height of 5-HT(Emax),which was significantly lower than that in the blank control group(P<0.05).The Emax of 5-HT in the Shuanglong Formular high,medium and low concentration groups(equivalent to 8,4,2 g crude drug/L)was significantly lower than that in the blank control group(P<0.01).The Emax of thromboxane A2 receptor a gonist(U46619)in Shuanglong Formular high and medium concentration groups(equivalent to 8,4 g crude drug/L)was significantly lower than that in the blank control group(P<0.01).Conclusion Shuanglong Formular can significantly dilate blood vessels,and its mechanism is related to the inhibition of voltage-dependent calcium channel opening and activation of 5-HT and thromboxane A2 receptors.