去肾动脉交感神经对自发性高血压大鼠交感肾上腺系统的影响

Effects of renal artery denervation on sympathoadrenal system in spontaneously hypertensive rats

目的研究去肾动脉交感神经对自发性高血压大鼠肾上腺、下丘脑等神经内分泌器官交感神经活动的影响。方法16只12周龄的雄性自发性高血压大鼠随机分为去肾神经组(RDNX组)和假手术组(Sham组),8只12周龄的雄性Wistar大鼠作为正常对照组(WKY组)。RDNX组采用苯酚消蚀法进行双侧去肾动脉交感神经术,而Sham组和WKY组进行假手术。分别检测各组大鼠术前和术后2周的收缩压(SBP)、舒张压(DBP)、平均动脉压(MAP)、心率(HR)和血清去甲肾上腺素(NE)含量,以及术后肾、肾上腺和下丘脑NE含量,免疫组织化学法观察肾上腺髓质和下丘脑视旁核酪氨酸羟化酶(TH)染色情况。结果RDNX组和Sham组术前SBP、DBP、MAP高于WKY组(P<0.05);RDNX组与Sham组术前SBP、DBP、MAP差异无统计学意义(P>0.05);3组大鼠SBP、DBP、MAP术前与术后差值比较,差异有统计学意义(P<0.05);RDNX组SBP、DBP、MAP术前与术后差值大于Sham组和WKY组(P<0.05)。3组大鼠术后肾脏、肾上腺和下丘脑NE含量比较,差异有统计学意义(P<0.05),Sham组术后肾脏、肾上腺和下丘脑NE含量高于RDNX组和WKY组。免疫组织化学结果显示,3组大鼠术后下丘脑视旁核和肾上腺髓质TH蛋白表达量比较,差异有统计学意义(P<0.05),Sham组术后下丘脑视旁核细胞TH蛋白表达量高于RDNX组和WKY组,Sham组肾上腺髓质细胞TH蛋白表达最高,WKY组其次,RDNX组最低。结论去肾动脉交感神经可减少自发性高血压大鼠肾上腺、下丘脑等神经内分泌器官的交感神经活动,并显著降低动脉血压。

Objective To investigate the effect of renal artery denervation(RAD)on sympathetic nerve activity of neuroendocrine organs including adrenal glands and hypothalamus in spontaneously hypertensive rats(SHR).Methods Sixteen 12-week-old male SHR were randomly divided into 2 groups(n=8):RAD treated group(RDNX)and Sham operated group(Sham).Eight 12-week-old male Wistar-Kyoto rats were served as a normotensive control group(WKY).Bilateral RAD was induced by a chemical method with phenol in RDNX group,while Sham and WKY group underwent sham operation.Systolic blood pressure(SBP),diastolic blood pressure(DBP),mean arterial pressure(MAP),heart rates and the contents of norepinephrine(NE)in serum were measured for each group before the operation.2 weeks after the operation,SBP,MBP,MAP,heart rates and the contents of NE in serum were detected again.In addition,the NE contents in kidney,adrenal glands and hypothalamus was determined and the extyrosine hydroxylase(TH)stainings in adrenal medullas and hypothalamic paraventricular nucleus(PVN)were measured.Result The SBP,DBP and MAP of RDNX in RDNX and Sham group were much higher than WKY group before the operation(all P<0.05).The differences of SBP,DBP and MAP between RDNX and Sham group were not significant before the operation(all P>0.05).The differences of SBP,MBP and MAP between preoperation and postoperation among the 3 groups were significant(P<0.05);the differences of SBP,DBP and MAP between preoperation and postoperation in RDNX group were higher than WKY and Sham group(P<0.05).2 weeks after the operation,the differences of contents of NE in kidney,adrenal glands and hypothalamus were statistically significant among the 3 groups(P<0.05);the contents of NE in kidney,adrenal glands and hypothalamus of Sham group were higher than RDNX and WKY group.As shown on the result of immunohistochemistry,2 weeks after the operation,the differences of the expression of TH in adrenal medullas and PVN were significant among the 3 groups(P<0.05);the expression of TH in PVN of Sham group were higher than RDNX and WKY group;the Sham had the highest expression of TH in adrenal medullas,followed by the WKY,and the RDNX was the lowest.Conclusion RAD can decrease the sympathetic nerve activity in neuroendocrine organs including adrenal glands and hypothalamus,which is accompanied by a significant decrease in blood pressure.