一氧化氮合成酶抑制剂对麻醉犬等长收缩运动的血流动力学影响

目的：比较麻醉犬等长收缩运动(IE)中注入一氧化氮合成酶(N0S)抑制刑前后心率(HR)及相关心血管指标的变化，探讨一氧化氮(NO)及NOS对IE时血流动力学变化的调节作用。方法：成年健康杂种犬14只，在安静、IE3、6、9分钟，运动后5、10、20分钟时测定各项血液动力学指标；然后注入NOS抑制剂，重复原试验，测上述各时间点的血流动力学指标。结果：IE9分钟时HR上升明显(P＜0．05)，而注入NOS抑制剂后IE9分钟时HR下降明显(P＜0．05)。收缩压(SBP)，舒张压(DBP)在注入NOS抑制剂后3、6、9分钟的水平均高于注入前(均为P＜0．05)。在注入NOS抑制剂后心输出量(CO)变化不明显，每搏量(SV)明显上升(P＜0．05)。结论：NOS抑制剂降低麻醉犬等长收缩运动时的心率，同时升高血压。如NO不被抑制，对等长收缩运动是有利的。

Effect of nitric oxide synthase (NOS) inhibitor on hemodynamic indexes during isometric exercise in anaesthesia dogs

Objective: This experimental study observed the hemodynamic effect before and after injected nitric oxide synthase (NOS) inhibitor in anaesthesia dogs. Methods: Fourteen adult dogs performed IE by faradism stimulation. HR and hemodynamic indexes were measured during the experiment. Results: Heart rate increased at the point of IE 9 minute (P<0. 05) but decreased by injecting NOS inhibitor (P<0. 05). The level of blood pressure (BP) was higher than that before injecting NOS inhibition (P<0. 05). Cardiac output (CO) had no change. Stroke volume (SV) increased after injected NOS inhibition (P<0. 05). Conclusion: Nitric oxide synthase (NOS) inhibitor can decrease HR; simultaneously increase BP. If NOS was not inhibited, it is beneficial for isometric exercise.