Abstract:

Abstract:Objective  To observe the injury of skeletal muscle and apoptosis following limb ischemia reperfusion (LIR) in rats and investigate the protective mechanism of endothelin-A receptor antagonist BQ123 on the injury of skeletal muscle following LIR. Methods  Male Wistar rats were randomly divided into three groups (n = 8)：control group,IR group,BQ123+IR group.The contents of lactate dehydrogenase (LDH),creatine phosphate kinase (CK),malondialehyde (MDA)，initric oxide (NO),endothelin-1 (ET-1),and NO/ET-1 in plasma and the values of MDA,myeloperoxide(MPO),NO,ET-1,NO/ET-1,the percentage of DNA Chain% in  gastrocnemius tissues were measured.Immunohistochemistry (IHC) method was used to detect the expression of Caspase-3 in gastrocnemius tissues.Apoptosis was examined by means of TdT-mediated dUTP nick end labeling(TUNEL).Results  Compared with  IR  group,the levels of LDH,CK,MDA，ET-1 in plasma  in BQ123+IR group were decreased（P<0.01); the content of NO in plasma and the percentage  of NO/ET-1  were increased（P<0.01）,but the expression of Caspase-3 was obviously decreased （P<0.01）;the contents of MDA,MPO,ET-1 in gastroenemius tissues were decreased(P<0.01),the NO level,NO/ET-1,and the percentage of DNA chain were increased(P<0.05 or P<0.01);the expression of Caspase-3 in gastrocnemius tissues was signficantly decreased,and the apoptotic index (AI) in BQ123+IR group was also decreased （P<0.01）.Conclusion The endothelin-A receptor antagonist BQ123 hase protective effects on skeletal muscle  injury and apoptosis following  LIR in rats.

Key words: reperfusion injury;muscle,skeletal；endothelin-1；apoptosis