心肌缺血／再灌注损伤后血清和心肌组织Leptin水平的变能

目的：观察大鼠心肌缺血／再灌注损伤对血清和心肌组织瘦素（Leptin）表达的影响,探讨Leptin在心肌缺血／再灌注损伤中的作用。方法：建立大鼠心肌缺血／再灌注模型,检测血清乳酸脱氢酶（LDH）和Leptin浓度,并用HE染色和免疫组织化学观察心肌组织病理学及Lepfin表达水平。结果：缺血组、再灌注组血清LDH水平显著升高（P〈0．05）,表明该模型制作成功,造成心肌局部一定程度的损伤。缺血组血清Leptin含量（6．34±2．49）ng／ml显著低于对照组（7．50±2．93ng／ml,P〈0．05）;再灌注后Leptin水平缓慢恢复,于再灌注2h时Leptin达到（8．32±1．74）ng／ml,恢复到损伤前水平（8．38±2．56）ng／ml,且随再灌注时间延长有升高趋势。免疫纽化显示与假手术纽心肌Leptin蛋白表达水平相比,其他四组均有显著降低（P〈0．01）,按缺血45min后再灌注1h组、缺血45min后再灌注3h组、单纯缺血45min组、缺血45min后再灌注2h组依次递减。结论：Leptin在心肌缺血／再灌注损伤后早期45min血中有明显减少,心肌组织中也明显表达下降。心肌组织病理损伤与Leptin的改变可能有一定的关系。

Changes of leptin levels in serum and myocardium after myocardial ischemia/reperfusion injury

Aim： To explore the effect of rat myocardial ischemia/reperfusion injury on leptin levels in serum and myocardium, and discuss the role of leptin in myocardial ischemia/reperfusion injury. Methods： A myocardial ischemia/reperfusion injury model of rats was estabilished, senan lactate dehydrogenase（LDH） and leptin levels were detected, and histopathological changes and leptin expressions in myocardium were investigated by hematoxylin-eosin staining and immunohistochemistry, respectively. Results： Serum LDH of ischemia and reperfusion groups increased significantly（P 〈 0.05）, suggesting the model was successfully established and a certain degree of local myocardial injury was induced. Serum leptin of ischemia group（6.34 ± 2.49） ng/ml was significantly lower than control group（7.50 ± 2.93 ng/ml, P 〈 0.05）. Leptin levels recovered gradually after reperfusion, reached（8.32 ± 1.74）ng/ml at 2 h after repeffusion, which recovered to the level before injury （8.38 ± 2.56）ng/nd, and showed a trend to increase as reperfusion time was elongated. Immunohistochemistry results showed that as compared with sham-operation group, myocardial leptin protein expressions of the other four groups were all significantly lower（ P 〈 0.01 ）, and decreased in order by 45 min ischemia/1 h reperfusion, 45 min ischemia/3 h reperfusion, 45 min ischemia and 45 min ischemia/2 h reperfu±sion. Conclusion： Leptin level in the blood decreases significantly at the early 45 min after myocardial ischemia/reperfusion injury, and its expression in myocardium also decreases significantly. There may be a certain relationship between the pathological injury of myocardium and the changes of leptin.