Abstract
This study was designed to explore the effects of long-term renal denervation (RDN) on blood pressure and renal function in spontaneously hypertensive rats (SHR). RDN was performed in bilateral renal arteries with 10% phenol in absolute ethanol in SHR and Wistar-Kyoto rats (WKY) at 13 weeks. Age-matched SHR and WKY served as controls. Blood pressure was measured. Plasma, urine and kidneys were collected 8 months after the RDN operation. Plasma renin activity (PRA), aldosterone levels, reactive oxidative stress, renal function and structural remodeling were assessed. RDN-treated SHR demonstrated a lower spontaneous rise in systolic blood pressure than rats in the SHR-Sham group (P < 0.01, at 20, 27, 34 and 41 weeks), except at 48 weeks (198.2 ± 12.9 vs 209.4 ± 11.9 mmHg, P = 0.145). WKY were not affected by RDN. Renal tissue norepinephrine was decreased by RDN in both SHR and WKY. Plasma PRA activity, aldosterone levels, and NAD(P)H oxidase activity were reduced by the RDN in SHR. Plasma eNOS and NO were increased by RDN only in SHR. The renal nerve was destroyed by RDN with no regeneration after 8 months. The progression of renal dysfunction associated with urinary protein excretion, glomerular sclerosis, and tubulointerstitial fibrosis was attenuated by RDN only in SHR through downregulation of the ACE/Ang II/AT1R axis and upregulation of the ACE2/Ang-(1-7)/MasR axis in the kidney. Thus, RDN delays the onset of hypertension and ameliorates glomerular sclerosis and tubulointerstitial fibrosis in SHR.