Role of afferent and efferent renal nerves in the antihypertensive effect of renal denervation in Ang II‐salt hypertension (856.4)

• DOI: 10.1096/fasebj.28.1_supplement.856.4
• Publication Date: 2021-06-16T09:56:51Z
• Authors: Jason Foss; Tim Mayerhofer; Laurel Wood; John Collister; John Osborn
• Keywords: 0303 health sciences; 03 medical and health sciences

Renal denervation (RDNX) attenuates drug resistant hypertension (HT) in humans, but it is unclear whether this is due to ablation of afferent or efferent renal nerves. We have previously shown that RDNX attenuates the intravenous (IV) AngII‐salt model of HT in the rat. The present study tested the hypothesis that the antihypertensive effect of RDNX in the IV AngII‐salt model is due to ablation of afferent renal nerves, specifically. Male Sprague Dawley rats underwent SHAM surgery, RDNX or selective ablation of afferent renal nerves by periaxonal capsaicin (renal‐CAP). Rats were instrumented with an IV catheter for delivery of AngII and a radio‐telemeter to measure mean arterial pressure (MAP) and heart rate (HR). Rats were placed on a 4% NaCl diet and, after recovery and a baseline period, AngII was infused IV (10 ng/kg/min) for 16 days. Rats were then sacrificed and kidneys were harvested and assayed for the efferent nerve marker, norepinephrine and the afferent nerve marker, CGRP. Initial results suggest that RDNX and renal‐CAP have similar antihypertensive effects in AngII‐salt rats. On the last day of AngII treatment, MAP was 161 ± 2.8 mmHg in SHAM (n = 4) rats, compared to 133 ± 11.5 mmHg in RDNX (n = 5) and 140 ± 5.2 mmHg in renal‐CAP (n = 4) rats. These preliminary results support the hypothesis that the antihypertensive effect of RDNX in the IV AngII‐salt model is primarily due to the ablation of afferent renal nerves.