无创性肢体预适应对缺血再灌注损伤大鼠心肌的保护作用

目的 观察大鼠无创性肢体预适应（RIP）后对心肌缺血再灌损伤后心肌形态学、梗死面积和心肌基质金属蛋白酶-2（MMP-2）、MMP-9和组织金属蛋白酶抑制剂-1（TIMP-1）的影响。方法 通过连续3d,每天1次3个循环下肢无创性5min缺血、5min再灌注,建立RIP模型。将大鼠随机分成3组,心肌缺血再灌组（I/R组）、心肌缺血预适应组（CIP组）和RIP组。以HE染色法观察心肌形态学改变;以红四氮唑染色法确定心肌梗死范围;以免疫组化法测定心肌MMP-2、MMP-9和TIMP-1的水平。结果 与I/R组比较,CIP和RIP均能明显改善心肌损害的形态学改变,降低心肌细胞的肿胀、减少间质出血和炎性细胞的浸润;显著降低心肌梗死面积（P〈0.01）;降低缺血区心肌MMP-2和MMP-9的水平,增加TIMP-1的水平（P〈0.05）。结论 RIP不仅能改善缺血再灌注损伤大鼠心肌形态学改变、减少心肌梗死面积,而且能降低心肌细胞基质的损伤,起到保护心肌的作用。

Protection of Limb Atraumatic Ischemic Preconditioning against Myocardium Ischemia/Reperfusion Injury in Rats

Objective AIM To observe the effect of limb atraumatic ischemic preconditioning(RIP) on myocardial morphologic changes,infarct size and matris metalloproteinases following myocardial ischemia-reperfusion (I/R) injury in rats.Methods RIP was performed in rats by a repeated three-cycle (5 min ischemia-5 min reperfusion) of hind limb everyday for three days.Three experimental groups were included:I/R,CIP and RIP.The morphologic changes were observed by HE dying,myocardial infarct size was measured with triphenyl tetrazolium choride (TTC),MMP-2,MMP-9 and TIMP-1 of myocardium in different areas were decided by immunohistochemistry.Results Compared with I/R,the myocardial swelling,interstitial hemorrhage and inflammatory cell infiltrate were decreased,the myocardial infarct size was reduced(P<0.01) after CIP and RIP.Immunohistochemic results showed that the level of MMP-2 and MMP-9 was higher, and the TIMP-1 was lower in I/R in ischemic area than that in non-ischemic area,while CIP and RIP could decrease the level of MMP-2,MMP-9 and increase the level of TIMP-1(P<0.05) .Conclusion RIP could protect against myocardial injury through reducing infarct size and decreasing myocardial matris injury.