过氧化物酶体增殖物激活受体α活化对急性心肌缺血性损伤的保护作用

目的 探讨过氧化物酶体增殖物激活受体α(PPARα)活化对异丙肾上腺素(Iso)所致大鼠急性心.肌缺血性损伤的保护作用及作用机制.方法 健康纯系雄性Wistar大鼠30只,体质量160～180 g.将大鼠按体质量随机分为3组.每组10只:①对照组;②Iso损伤组,采用腹腔内注射Iso复制急性心肌缺血损伤的动物模型;③非诺贝特(FF)保护组,在预先给予FF的基础上复制Iso致急性心肌缺血损伤的动物模型.比色法测定大鼠血清中肌酸激酶(CK)和乳酸脱氢酶(LDH)活性以及心肌组织中髓过氧化物酶(MPO)活性;Western blot法测定大鼠心肌组织中PPARα的蛋白表达水平.结果 大鼠血清CK活性:对照组、Iso损伤组、FF保护组分别为(62.41±9.47)、(101.71±11.05)、(75.64±11.73)kU/L,组问比较差异有统计学意义(F=34.34,P<0.01);Iso损伤组和FF保护组高于对照组(P<0.01或<0.05);FF保护组低于Iso损伤组(P<0.01).大鼠血清LDH活性:对照组、Iso损伤组、FF保护组分别为(5912.20±204.44)、(6365.78±137.10)、(6089.76±169.60)U/L,组间比较差异有统计学意义(F=17.54,P<0.01);Iso损伤组和FF保护组高于对照组(P<0.01或<0.05);FF保护组低于Iso损伤组(P<0.01).心肌组织中MPO活性:对照组、Iso损伤组、FF保护组分别为(1.95±0.10)、(3.89±0.17)、(2.49±0.19)U/g,组间比较差异有统计学意义(F=391.68,P<0.01);Iso损伤组和FF保护组高于对照组(P<0.01),FF保护组低于Iso损伤组(P<0.01).心肌组织中PPARα蛋白表达:对照组、Iso损伤组、FF保护组分别为251.57±10.95、191.97±10.74、215.08±9.61,组间比较差异有统计学意义(F=82.69,P<0.01):Iso损伤组和FF保护组低于对照组(P<0.01).FF保护组高于Iso损伤组(P<0.01).结论 PPARα被其配体FF活化后.对Iso所致大鼠急性心肌缺血性损伤具有保护作用,其机制可能与抑制炎症因子的产生,减轻炎症反应有关.

Protective effects of peroxisome proliferate-activated receptor α activation on acute myocardial damage

Objective To investigate the protective effects and molecular mechanism of peroxisome proliferate-activated receptor α(PPARα) activation on acute myocardial damage induced by isoproterenol (Iso) in rats. Methods Thirty male Wistar rats, weighting 160～180 g, were randomly divided into control group, Iso group, fenafibrate(FF) group(each n=10) according to physique quantity. Acute myocardial injury caused by Iso abdomen cavity injection induced ischemia was established and the protective effects of peroxisome proliferate-activated receptor α activation were accessed by the level of ereatine kinase(CK), lactic dehydrogenase(LDH) in serum as well as the activities of myoperoxidase(MPO) in myocardium, and the protein expressions of PPABα in myocardium by Western blot. Results The level of serum CK in control group, lso group and FF group, was (62.41±9.47),(101.71±11.05),(75.64±11.73)kU/L, respectively(F= 34.34, P<0.01). Whereas the level of serum CK in Iso group and FF group was higher than that in control group(P<0.01 or<0.05), the level of serum CK in FF group was lower than that in Iso group(P<0.01). The levels of LDH in these three groups were (5912.20±204.44), (6365.78±137.10), (6089.76±169.60) U/L, respectively(F= 17.54, P<0.01). Compared with the control group, the levels of LDH in Iso and Fir groups were significantly increased(P<0.01 or<0.05). But the level of LDH in FIr group was decreased compared with that in Iso group(P<0.01). The activities of myocardial MPO in these three groups were (1.95±0.10),(3.89±0.17),(2.49±0.19)U/g, espectively(F=391.68,P< 0.01). The activities of myocardial MPO in Iso and FF groups were higher than that in the control group (all P< 0.01), while the activities of myocardial MPO in FIr group were lower than that in lso group(P<0.01). The protein expressions of PPARα in myocardium of these three groups were 251.57±10.95,191.97±10.74,215.08±9.61, respectively(F=82.69, P<0.01). Conclusion PPARα activation by its actor FF can exert protective effects on the acute myocardial ischemia injury induced by lso in rats through inhibiting the release of inflammatory cell factors.