Abstract: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.