【摘要】 目的研究钙蛋白酶抑制剂ALLN对缺血-再灌注(I-R)大鼠心肌肌浆网钙泵(SERCA)功能的影响。方法 24只雄性SD大鼠随机分为正常灌注组(对照组)、I-R组、ALLN+I-R组和二甲亚砜+I-R组(DMSO+I-R组),分别检测再灌注15min时冠状动脉流出量(CF)和冠脉流出液中乳酸脱氢酶(LDH)漏出量;荧光分光光度计测定荧光强度来反映钙蛋白酶活性;分别采用改良p-NPP法和Millipore过滤技术测定SERCA的活性和ATP依赖的SERCA45Ca2+摄取率,免疫印迹法检测心肌细胞SERCA蛋白表达水平。结果与I-R组相比,ALLN+I-R组CF、SERCA蛋白表达水平、SERCA的活性和45Ca2+摄取率显著增高(P<0.01),而LDH漏出量和钙蛋白酶活性显著降低(P<0.01)。结论 ALLN对离体大鼠心脏I-R损伤有保护作用,与其抑制钙蛋白酶活性,一定程度减轻I-R损伤对SERCA功能及蛋白表达水平的影响有关。更多还原

【Abstract】 Objective To investigate the protective effects of calpain inhibitor(ALLN) on sarcoplastic reticulum Ca2+-ATPase(SERCA) in isolated ischemia-reperfusion(I-R) hearts of rat.Methods Twenty-four male SD rats were randomly divided into 4 groups of control,I-R,ALLN+I-R,and DMSO+I-R with 6 rats each.At 15 min after reperfusion,coronary flux(CF) and LDH were examined,the activity of calpain was detected by fluorospectrophotometer,and SERCA activity and 45Ca2+ uptake were evaluated with modified p-NPP and Millipore filting.The protein expression of SERCA was detected by immunoblotting.Results Compared with group I-R,CF,protein expression level and activity of SERCA and 45Ca2+uptake in group ALLN+I-R were all significantly increased(P<0.01),but LDH and the activity of calpain were significantly decreased(P<0.01).ConclusionALLN has a significant protective effect on I-R injury of isolated hearts,which could be associated with the depression of calpain activity and reduction of the effect of I-R injury on the protein expression of SERCA.更多还原