N-硝基左旋精氨酸及氯沙坦对家兔实验性心肌梗塞的心功能影响

Effects of L-NNA and losartan on left ventricular function aftermyocardial infraction in experimental rabbits

目的 :探讨N -硝基左旋精氨酸 (L -NNA)及氯沙坦 (losartan)对家兔急性心肌梗死过程中心功能的影响。方法 :健康家兔 2 4只随机分为 4组 (n =6 ) :①假手术对照组 ,②急性心肌梗死组 ,③急性心肌梗死 +L -NNA组 ,④急性心肌梗死 +losartan组。结扎冠状动脉左前降支造成急性心肌梗死的模型。实验中连续观察各组心肌梗死前、心肌梗死 15min、30min、6 0min、90min的心功能变化。结果 :与急性心肌梗死组相比 ,L -NNA及losartan组的家兔左心室内压变化最大速率 (±dp/dtmax)、左心室收缩压 (LVSP)、左心室平均压 (LVAP)、左心室心肌收缩成分最大缩短速度 (Vmax)有不同程度的升高 (P <0 .0 5 ,0 .0 1) ,左室舒张末压 (LVEDP)有不同程度的的降低 (P <0 .0 5 ,0 .0 1)。结论 :L -NNA及losartan可改善急性心肌梗死时的心功能 ,对缺血的心肌具有保护作用 ,其作用可能与NO的产生量有关。

Objective: To investigate the effects of L-NNA and losartan on the left ventricular(LV) function after myocardial infraction in rabbits.Methods:Rabbits were randomly divided into sham-operated control group(SO), acute infract group(AI), L-NNA pretreatment group,and losartan pretreatment group. The left anterior descending(LAD) branch of coronaryartery was ligated to develop acute ischemic model. The systolic and diastolic of LV was measured before and at 15,30,60,90min after ligating LAD respectively. Results: Compared with AI group , the results showed that ±dp/dtmax, LVSP,LVAP,Vmax of L-NNA group and losartan group increased markedly(P<0.05,0.01);LVEDP decreased obviously(P<0.05,0.01). Conclusions: L-NNA and losartan can improve the LV function and protect ischemic myocardium . The effects may be associated with the content of NO.