运动训练联合基因治疗对肾性高血压大鼠肾功能的影响

Effects of exercise training combined with β1 adrenoceptor antisense gene therapy on blood pressure and renal function in renal hypertensive rats

目的观察运动训练联合β1肾上腺素能受体基因治疗对肾性高血压大鼠血压、肾功能、肾脏前肾素原mRNA、肾脏β1受体mRNA和蛋白的影响，探讨其改善肾功能的机制。方法两肾一夹法制作肾性高血压模型，基因治疗采用经鼠尾静脉注射阳离子脂质体与β1反义寡核苷酸方法。检测大鼠血压、肾功能变化。半定量RT—PCR测定肾脏β1受体mRNA、前肾素原mRNA水平。Western印迹法测检肾脏β1受体的蛋白水平。结果与模型组比较，运动联合基因治疗可使血压下降并维持4周，血压下降最高达41mmHg；尿蛋白量[（45．82±6．56）比（29．12±5．22）mg／L，P〈0．01】、BUN[（13．10±2．62）比（9．05±1．84）mmol／L，P〈0．05]显著降低（P〈0．01，P〈0．05）；内生肌酐清除率显著升高（P〈0．01）；前肾素原mRNA、β1受体mRNA、蛋白表达水平显著降低（P〈0．05）。结论运动训练联合β1受体反义基因治疗可以明显地降低血压，改善肾功能；且运动训练可以增强基因治疗对β1受体mRNA和蛋白的抑制作用，在转录和翻译水平抑制过度激活的β1受体的表达。

Objective To evaluate the effects of exercise training combined with β1 adrenoceptor antisense gene therapy on blood pressure, renal function, preprorennin mRNA, β1 adrenoceptor mRNA and protein in Goldblatt hypertensive rats. Methods Liposome and β1- AS-ODNs were injected intravenously in rats with 2 kidney 1 clip （2K1C） hypertension. Renal function and blood pressure were measured. Levels of renal β1 adrenoceptor and preprorenin mRNA were tested by RT-PCR and the level of β1 adrenoceptor protein was tested by Western blotting. Results On the basis of the magnitude and duration of hypotension, exercise training combined with β1-AS-ODN decreased blood pressure by up to 41 mm Hg for 4 weeks. Compared with the 2K1C group, the levels of urine protein [（45.82±6.56） vs. （29.12±5.22） mg/L, P〈0.01] and BUN [（β.10±2.62） vs. （9.05：t=1.84） mmol/L, P〈0.05] were significantly decreased respectively and Ccr was significantly increased （P〈0.01） in exercise training combined with β1-AS-ODN group. Exercise training combined with β1-AS-ODN significantly decreased the levels of preprorenin mRNA, myocardial β1 adrenoceptor mRNA and protein （P〈0.05, P〈0.05, P〈0.05, respectively）. Conclusion Exercise training combined with β1-AS-ODN can significantly ameliorate blood pressure and renal function in hypertensive rats, which is associated with the reducing levels of renal β1 adrenoceptor mRNA and protein. The inhibition of overactive β1-adrenoceptor expression probably occurs in transcription and post-transcriptional stages.