不同浓度的L-精氨酸在心肌缺血再灌注损伤中的不同效应

Effect of L-Arginine-NO pathway in myocardial ischemia and reperfusion in isolated langendorff rat heart model

目的 观察L 精氨酸—一氧化氮途径 (L Arg NO)是否对心肌再灌注损伤有影响 ,以及不同浓度的L 精氨酸 (L Arg)的不同效应。 方法 将 4 8只雄性SD大鼠随机分为 6组 ,缺血对照组、1mM组、3mM组、10mM组、30mM组、10 0mM组 ,进行离体心脏灌流实验观察缺血前及再灌注后左心功能 ,冠脉流出液中乳酸脱氢酶 ,心肌ATP含量。结果 1mM组 ,3mM组再灌注后心功能指标 ,心肌酶溢出量 ,心肌组织ATP含量 ,以及心肌细胞超微结构均较对照组为佳。 10mM组、30mM组再灌注后心功能恢复率、心肌组织ATP含量 ,电镜超微结构与对照组相比无明显差异。 10 0mM组再灌注后心肌酶溢出量较对照组明显增高。结论 (1)在缺血前予 1mM、3mM的L Arg能减轻再灌注损伤 ;(2 )而给予高于 3mM的L Arg并不能减轻再灌注损伤 ,10 0mM组甚至加重了再灌注损伤 ,说明L

Objective To evaluate the effect of pretreatment with nitric oxide precursor(L Arg) before ischemia on recovery with reperfusion in rat hearts.Methods After 20min of stabilization,forty eight male rat hearts were randomized into six groups.Isolated hearts were subjected to 20min normothermic global ischemia followed by 30min reperfusion(Gr.1).The other groups (Gr.2 6) received 1mM,3mM,10mM,30mM and 100mM L arginine before global ischemia respectively.Results At 30min of reperfusion,compared to control,1mM and 3mM L arginine groups(Gr.2 and Gr.3)exhibited a significant improved recovery of LVSP(mmHg)(119 0±6 6,112 0±5 8 respectively,vs Gr l 84 0±4 2, P< 0 05).Significant recovery improvement was observed also in other hemodynamic paramenters(±dp/dtmax),as well as biochemical recovery by LDH,ATP.The 10mM,30mM and 100mM groups had a significant poorer hemodynamic and biochemical recovery.Conclusion These results demonstrate L arginine(1mM,3mM)has the cardiprotective effect in ishemia reperfusion injury.On the other hand,L arginine(higher than 3mM) has no cardioprotective effect.