去肾神经对中年自发性高血压大鼠血压的影响

目的 研究去肾神经对中年自发性高血压大鼠血压的影响.方法 30周龄自发性高血压大鼠(spontaneous hypertensive rats,SHR)及正常血压大鼠(Wistar kyoto rats,WKY)各25只,按随机区组设计分为5组,根据观察时间分为1、4、9、16、32 d组(n=10),于第2天行去肾神经术.无创鼠尾血压仪(BP-98A)测量血压；10％苯酚乙醇溶液去肾神经；ELISA法测定肾组织中去甲肾上腺素(nonadrenaline,NE)含量及肾素活性；RT-PCR法和Western blot法测定大鼠腹主动脉α1、p1-肾上腺素能受体(α1、β1-受体)在mRNA和蛋白水平上的表达水平.结果 未去肾神经的中年SHR血浆及肾组织NE含量及肾素活性水平明显高于中年WKY(P ＜0.05),主动脉α1、β1-受体mRNA和蛋白的表达与同龄的WKY差异无显著性(P＞0.05)；去肾神经急性期,中年SHR血压迅速下降(P＜0.05),血浆与肾组织NE含量及肾素活性降低(P＜0.05)；主动脉α1-受体mRNA和蛋白表达上调(P＜0.05),β1-受体mRNA和蛋白表达差异无显著性(P＞0.05)；慢性期,肾组织NE含量和肾素活性升高(P＜0.05),主动脉α1、β1-受体mRNA和蛋白表达均上调(P＜0.05).去肾神经对中年WKY无显著性影响(P＞0.05).结论 去肾神经对于中年SHR大鼠的降压效应是暂时的,急性期血压下降,α1-受体表达上调,β1-受体表达无变化；慢性期血压升高,α1、p1-受体表达均上调；血压的变化与NE及肾素活性的变化一致.

Renal denervation in treatment of spontaneous hypertension in adult rats

Objective To determine the effect of renal denervation on hypertension in the middle-aged rats.Methods A total of 25 spontaneous hypertension rats(SHR) and 25 Wistar kyoto rats(WKY) aging 30-week-old male rats,weighing 350 to 420 g were randomly divided into 5 groups randomly,that is,1-day group,4-day group,9-day group,16-day group,and 32-day group(n=10,including 5 SHR and 5 WKY rats in each group).The implementation of the renal denervation was on the second day with 10% phenol ethanol solution.Blood pressure was measured by a non-invasive tail blood pressure meter(BP-98A).The plasma and renal tissue norepinephrine(nonadrenaline,NE) content and rennin activity were detected by ELISA.The expression of α1-and β1-adrenoreceptor(α1-R and β1-R)in rat aortic smooth muscle were determined by RT-PCR and Western blotting respectively for their mRNA and protein levels.Results NE content and renin activity in the plasma and renal tissue were significantly higher in middle-aged SHR than in middle-aged WKY rats(P<0.05).However,the expression of the aorta α1-R and β1-R at the mRNA and protein levels had no significant difference in middle-aged SHR and WKY rats(P>0.05).Rapid decline in blood pressure was observed in middle-aged SHR after denervation(P<0.05),and NE content and renin activity in the plasma and renal tissue was significantly decreased(P<0.05),but the expression of the aorta α1-R was up-regulated(P<0.05),and β1-R had no difference(P>0.05).In the chronic denervation period,the blood pressure as well as renal NE content and renin activity were gradually higher than normal levels(P<0.05).The expression of α1-R and β1-R were up-regulated which ultimately higher than initial levels(P<0.05).The expression of α1-R and β1-R protein was similar with the expression of mRNA.Conclusion Renal denervation attenuates the high blood pressure temporarily in the middle-aged SHR.During the acute period,α1-R is up-regulated.However,blood pressure is gradually increased in chronic period with the up-regulation of α1-R and β1-R.Changes in the blood pressure are consistent with the changes in the NE and renin activity.