不同时期肢体缺血对缺血再灌注心肌PPARβ/δ表达的影响

Impacts of limb ischemia in different periods on the expression of MI-R PPARβ/δ

目的在大鼠心肌缺血再灌注不同时期(心肌缺血前、心肌缺血同时、心肌缺血再灌注同时)给予远隔肢体缺血处理,比较大鼠血清CK-MB、cTnI和心肌PPARβ/δmRNA和蛋白表达水平的差异。方法 40只健康雄性Wister大鼠,均进行心肌缺血再灌注处理,根据下肢缺血的处理不同,随机分为4组:单一心肌缺血再灌注对照组(MI-R组)、心肌缺血期远隔肢体处理组(RLIPerC)、心肌缺血前远隔肢体处理组(RLIPreC)、心肌缺血再灌注时远隔肢体处理组(RLIPostC)。实验结束后,留取各组血清和缺血部位心肌组织标本,采用ELISA法检测血清CK-MB和c TnI含量,逆转录酶多聚酶链反应(RT-PCR)检测心肌PPARβ/δmRNA表达水平,Western blot方法检测PPARβ/δ蛋白水平。结果与MI-R组相比,RLIPerC、RLIPreC、RLIPostC组CK-MB和cTnI明显降低(P <0.05),心肌PPARβ/δmRNA和蛋白表达均升高(P <0.05)。血清CK-MB、cTnI含量、心肌PPARβ/δmRNA和蛋白表达在RLIPerC、RLIPreC、RLIPostC各组之间无明显差异(P> 0.05)。结论在大鼠心肌缺血再灌注不同时期,给予间断多次远隔肢体缺血再灌注处理,均可减轻心肌损伤,提高心肌PPARβ/δmRNA和蛋白表达水平。心肌PPARβ/δ表达增加可能对缺血再灌注心肌有保护作用。

Objective To treat remote limb ischemia in different periods of myocardial ischemia reperfusion(MI-R) in rats(before myocardial ischemia, during myocardial ischemia and during MI-R) and compare the difference in the levels of serum CK-MB,cTnI and the mRNA and protein expression levels of myocardial PPARβ/δ. Methods A total of 40 healthy male Wister rats were treated with MI-R and were randomly divided into four groups according to different treatment of lower limb ischemia: single MI-R control group(MI-R group), myocardial ischemic remote limb ischemia treatment group(RLIPerC group), premyocardial ischemic remote limb ischemia treatment group(RLIPreC group) and intra-MI-R remote limb ischemia management group(RLIPostC group).After the experiment, the serum and myocardial tissue samples were collected from each group. ELISA was taken to detect the content of serum CK-MB and c TnI; reverse transcriptase polymerase chain reaction(RT-PCR) was adopted to detect the m RNA expression levels of myocardial PPARβ/δ; Western blot method was applied to detect the protein level of PPARβ/δ. Results Compared with MI-R group, the CK-MB and c TnI in RLIPerC, RLIPreC and RLIPostC groups were significantly lower(P < 0.05), but mRNA and protein levels of myocardial PPARβ/δ were higher(P < 0.05). There was no significant difference in serum CK-MB, cTnI content,mRNA and protein expression of myocardial PPARβ/δ among RLIPerC, RLIPreC and RLIPostC groups(P >0.05). Conclusion Discontinuous multiple ischemic reperfusions of the remote limb ischemia in different periods of MI-R in rats can alleviate myocardial injuries and improve the mRNA and protein expression levels of myocardial PPARβ/δ. The increased expression of myocardial PPARβ/δ may have protective effects on myocardium treated with ischemia-reperfusion.