热休克蛋白70对大鼠离体心脏细胞凋亡的影响

The effects of heat shock protein 70 on myocardial cell apoptosis in isolated rat hearts

目的观察热休克蛋白70（HSP70）对离体大鼠供心心肌细胞凋亡相关蛋白bcl-2、bax表达的影响。方法Wistar大鼠18只，分为2组：对照组（C，n=9），腹腔注射生理盐水0．5ml，24h后取离体心脏灌注HTK心脏保护液，4cC保存3h后建立Langendorff离体心脏灌注模型，灌注KH液2h；实验组（E，n=9）腹腔注射重酒石酸去甲肾上腺素（溶于生理盐水中）3．1μmol／kg（0．53mg／kg），腹腔注射24h后取离体心脏，处理方法同c组。运用免疫组织化学sP法测定心肌HSP70含量、bcl-2、bax蛋白的含量并做统计学处理比较。结果HSP70含量E组（17．784±1．82）较C组（5．22±1．05）明显增高（P〈0．01），bcl-2的表达E组（41．88±5．09）较C组（31．36±3．27）明显增多（P〈0．01），bax的表达E组（22．61±3．49）较C组（40．52±4．17）明显减少（P〈0．01），bcl-2／bax比值E组（1．86±0．11）较c组（0．77±0．01）明显增高（P〈0．05）。结论心肌HSP70高表达能促进心肌抗凋亡蛋白bcl-2的表达，减少促凋亡蛋白bax表达，增加bcl-2／bax比率，抑制心肌细胞凋亡。

Objective To investigate the effects of heat shock protein 70 （HSP70） on myocardial cell apoptosis in isolated rat hearts. Methods Eighteen Wistar rats were randomly divided into 2 groups. In control group （ C, n = 9）, 0.5 ml normal saline was injected intraperitoneally, and 24 h later isolated hearts were stored in 4 ℃ for 3 h with Histidine-tryptophan-ketoglutarate （HTK） solutions,and then perfused for 2 h by Langendorff model with Krebs-Henseleit （K-H） solutions. In experimental group （E, n = 9） , noradrenaline bitartrate （3.1 μmol/kg,0.53 mg/kg） was injected intraperitoneally, and 24 h later isolated hearts were stored in 4 ℃ for 3 h with HTK, and then perfused for 2 h with Krebs-Henseleit （ K- H） solutions by Langendorff model. HSP70 content ,myocardial cell apoptosis ,the expression of bcl-2 protein and bax protein were detected. Results HSP70 and bel-2 contents in E group （ 17.78±1.82,41.88 ±5.09） were higher than those in C group （5.22 ± 1.05,31.36±3.27） （P 〈0.01 ）. The expression level of bax protein in E group （22.61 ＋3.49） was lower than in C group （40.52 ±4.17）. Conclusion HSP70 can affect the expression of myocardial bcl-2 and bax proteins,and inhibit myocardial cell apoptosis.