瘦素对窒息新生大鼠心肌组织calpain-1和Bcl-2的表达及细胞凋亡的影响

目的 研究瘦素对窒息新生大鼠心肌组织钙依赖中性蛋白酶（calpain-1）、B 淋巴细胞瘤-2（Bcl-2）的表达及心肌细胞凋亡的影响。方法 将48 只新生大鼠随机分为正常对照组、窒息组、瘦素处理组（L20 组、L80 组、L160 组）和calpain-1 抑制剂组（CAI-1 组）。建立新生大鼠常压窒息模型，各瘦素处理组在造模后立即给予瘦素20、80、160 μg/kg 进行腹腔注射，CAI-1 组造模后立即给予calpain-1 抑制剂10 mg/kg 腹腔注射。各组均在造模完成后2 h 取心肌组织，免疫组化法检测calpain-1、Bcl-2 的表达，Tunel 法检测心肌细胞凋亡指数（AI）。结果 窒息组calpain-1、Bcl-2 的表达及AI 值较正常对照组均明显升高（P P P > 0.05）；窒息后各组calpain-1 与AI 值呈正相关，Bcl-2 与calpain-1 和AI 值均呈负相关（P 结论 瘦素可抑制calpain-1 的活化，上调Bcl-2 表达，从而减少窒息新生大鼠心肌细胞凋亡。

Effect of leptin on expression of calpain-1 and Bcl-2 and apoptosis in myocardial tissue of neonatal rats after asphyxia

Objective To study the effect of leptin on the expression of calcium-activated neutral protease 1 (calpain-1) and B cell lymphoma-2 (Bcl-2) and apoptosis in the myocardial tissue of neonatal rats after asphyxia. Methods A total of 48 neonatal rats were randomly and equally divided into normal control group, asphyxia group, leptin treatment groups, and calpain-1 inhibitor (CAI-1) group. The neonatal rat model of asphyxia under normal atmospheric condition was established in all groups except the control group. For the leptin treatment groups, rats received 20, 80, and 160 μg/kg leptin by intraperitoneal injection immediately after model establishment, respectively. For the CAI-1 group, rats received 10 mg/kg CAI-1 by intraperitoneal injection immediately after model establishment. For all the groups, the myocardial tissue was collected at 2 hours after model establishment. Immunohistochemistry was used to measure the expression of calpain-1 and Bcl-2. The TUNEL method was used to evaluate apoptosis of myocardial cells. Results The expression of calpain-1 and Bcl-2 and apoptosis index (AI) were significantly higher in the asphyxia group than in the normal control group (P P P Conclusions Leptin reduces apoptosis of myocardial cells in asphyxiated neonatal rats by the inhibition of calpain-1 activation and upregulation of Bcl-2 expression.