镁对缺血再灌注心脏内皮细胞功能和血小板活化的影响

Effect of Magnesium on Endothelium and Platelet Activation in Rabbit Model with Ischemia-Reperfusion of Heart

为探讨心肌缺血再灌注时内皮细胞功能和血小板活化状态及硫酸镁对它们的影响 ,将新西兰大耳白兔32只分为 4组。对照组在左冠状动脉前降支中上 2 / 3处穿线 ;缺血组于同一位置持续结扎血管 ;再灌注组及治疗组结扎 0 .5h后再灌注。治疗组于结扎后静滴硫酸镁溶液 ,其余各组静滴等量生理盐水。于结扎前、缺血 0 .5h、再灌注 1h及 4h采血 ,用火焰原子吸收法测定血浆Mg2 + 浓度 ,硝酸还原酶法测定血浆一氧化氮浓度 ,放射免疫法测定血小板表面α颗粒膜蛋白 140。发现 :①对照组手术前后血浆Mg2 + 、一氧化氮浓度和血小板表面α颗粒膜蛋白140分子数差别无统计学意义 (P >0 .0 5 ) ;②缺血组、再灌注组心肌缺血 0 .5h ,血浆Mg2 + 、一氧化氮浓度较术前及对照组相应时间显著降低 (P <0 .0 5 ) ,并随时间延长呈进行性下降 ,而血小板表面α颗粒膜蛋白 140分子数显著升高 (P <0 .0 5 ) ,并随时间延长进一步上升 ;③治疗组应用硫酸镁后 ,血浆Mg2 + 、一氧化氮浓度较缺血组、再灌注组相应时间明显升高 ,而血小板表面α颗粒膜蛋白 140分子数明显降低 ,但仍高于对照组 (P <0 .0 5 )。提示缺血再灌注过程中存在内皮细胞功能损伤及血小板活化 ,硫酸镁可能有保护内皮细胞和抑制血小板活化的作用。

Aim To investigate the endothelial function and platelet activation during myocardial ischemia-reperfusion injury and the protective effect of magnesium. Methods Thirty-two rabbits were randomly divided into four groups. In control group the left anterior descending coronary artery (LAD) was falsely ligated. In ischemia group the LAD was ligated. Rabbits in reperfusion group and therapy group underwent 0.5 h of LAD occlusion and 4 h of reperfusion. After LAD ligation rabbits in therapy group were intravenously given magnesium sulfate and rabbits in the rest groups were given 0.9% sodium chloride. The level of plasma Mg 2+, nitric oxide (NO) and the number of alpha-granule membrane protein-140 (GMP-140) molecule on platelet surface were measured before LAD ligation and after ischemia for 0.5 h, reperfusion for 1 h and 4 h. Results ①The plasma concentrations of Mg 2+, NO and the number of GMP-140 molecule on the platelet surface in control group were of no statistical difference before and after false LAD ligation (P>0.05); ②The level of Mg 2+, NO were significantly decreased and the number of GMP-140 molecule on platelet surface was increased after myocardial ischemia/ischemia-reperfusion in ischemia group, reperfusion group compared with those before LAD ligation and those at the same time in control group (P<0.05); ③The level of Mg 2+,NO was increased and GMP-140 was decreased in therapy group compared with those in ischemia group and reperfusion group (P<0.05). Conclusions It suggests that there is endothelial dysfunction and platelet activation during ischemia-reperfusion. Sulfate magnesium might be useful in protecting endothelium and inhibiting platelet activation.