Bilateral Renal Cryodenervation Decreases Arterial Pressure and Plasma Renin Activity in Fructose‐Fed Sprague Dawley Rats

Abstract

High consumption of fructose containing foods is increasingly prevalent. Fructose intake is associated with metabolic syndrome including hypertension. Fructose upregulates renal sodium and chloride reabsorption. When combined with high salt diet, fructose‐fed rats display increased arterial pressure and renal sympathetic nerve activity (RSNA). We tested the hypothesis that bilateral renal denervation using cryo‐techniques will decrease arterial pressure and plasma renin activity (PRA) in fructose‐fed rats on high salt diet. Male Sprague Dawley rats were instrumented with radiotransmitters for heart rate and arterial pressure. They were placed on 20% fructose (FF) in their drinking water and 0.4% NaCl diet. After 1 week they were maintained on 0.4 % (LS) or switched to 4% NaCl (HS) diet. One week later, rats were subjected either to bilateral denervation by freeze (−150°C)‐thaw × 3 (cryoDNX) or sham denervation (shamDNX). After 7–10 days, aortic blood was taken for PRA and renal cortex tested for norepinephrine content to verify denervation. Mean arterial pressure (MAP) increased by 9.6 ± 1.0 Hg in FF‐HS vs 0.8 ± 0.7 in FF‐LS rats. MAP decreased from 114.8 ± 2.9 to 108.5 ± 2.0 mmHg in FF‐HS‐cryo but did not change in FF‐HS‐sham rats, 115.6 ± 2.6 mmHg. PRA was higher in FF‐LS‐shamDNX 35.1 ± 13.2 vs FF‐HS‐shamDNX 10.9 ± 5.5 ng AngI/hr/ml and decreased significantly after cryodenervation in both groups. These findings support the concept that high fructose associated with high salt diet leads to renin dependent hypertension which is mediated, at least in part, by increased renal sympathetic nerve activity.Support or Funding InformationVA Merit Award to NFR