【摘要】 目的研究N硝基左旋精氨酸(L-NNA)对麻醉大鼠血流动力学的影响。方法将32只SD大鼠随机分为4组:L-NNA 0.5mg/kg组、L-NNA 1mg/kg组、L-NNA 2mg/kg组和生理盐水对照组。静脉方式给药,用股动脉插管、右颈总动脉心室插管和连续记录肢体Ⅱ导联心电图的方法观察给药前和后5、15、30和60分钟大鼠的心率(HR)、收缩压(SBP)、舒张压(DBP)、平均动脉血压(AP)、左心室收缩压(LVSP)、左心室舒张压(LVDP)、左心室平均压(LVAP)、左心室终末舒张压(LVEDP)、左心室内压最大上升速率(+dp/dt max)、左心室开始收缩至dp/dt max的间隔时间(t-dp/dt max)、左心室内压最大下降速率(-dp/dt max)和等容舒张时间室内压下降的时间常数(T)的变化。结果静脉注射L-NNA 0.5、1和2 mg/kg 5、10和30分钟均能使大鼠心率显著加快(P<0.05),SBP升高(P<0.05或P<0.01),LVSP显著升高(P<0.05或P<0.01),对LVDP、-dp/dt max、t-dp/dt max和T值无显著性影响(P>0.05);静脉注射L-NNA 1和2 mg/kg后5、15和30分钟均能使麻醉大鼠DBP、AP、LVAP和+dp/dt max明显升高(P<0.05或P<0.01),对LVDP、LVEDP、t-dp/dt max、-dp/dt max和t值无显著影响(P>0.05)。结论N硝基左旋精氨酸有加快麻醉大鼠心率,升高动脉血压、增强心肌收缩功能的作用。更多还原

【Abstract】 Objective To study the effects of L-NNA on the hemodynamics in rats.Methods Thirty-two SD rats were divided into four groups randomly:1st group(L-NNA 0.5mg/kg),2nd group(L-NNA 1mg/kg),3rd group(L-NNA 2mg/kg) and contrasted group(NS).Changes of hemodynamics parameters including HR,SBP,DBP,AP,LVSP,LVDP,LVAP,LVEDP,+dp/dt max,t-dp/dtmax,-dp/dtmax and T were recorded by cannulating femoral artery,right common carotid artery and consecutive electrocardiographic Ⅱ.(Results) In L-NNA groups(0.5 mg/kg,1 mg/kg and 2mg/kg iv),HR,SBP and LVSP were increased significantly in 5,10 and 30 mintues(P<(0.05);)there were no significantly changes of LVDP,-dp/dtmax,t-dp/dt max and T(P>(0.05).)In L-NNA groups(1(mg/kg) and 2(mg/kg) iv),DP,AP,LVAP and +dp/dtmax were increased greatly in 5,15,30 minutes(P<0.05 or P<0.01);there were no significantly changes of LVDP,LVEDP,t-dp/dtmax,-dp/dtmax and T(P>0.05).Conclusion L-NNA can improve HR and BP in rats.It has better increased effects on myocardial contraction in rats.更多还原