Effects of renal sympathetic denervation using saline-irrigated radiofrequency ablation catheter on the activity of the renin-angiotensin system and endothelin-1

INTRODUCTION: Excessive activation of the sympathetic nervous system (SNS) and the renin-angiotensin system (RAS) are crucial and interacted closely in the pathogenesis of chronic cardiovascular diseases. This study investigated the effects of renal denervation (RDN) on the RAS. MATERIALS AND METHODS: Eight Chinese Kunming dogs underwent bilateral RDN utilizing saline-irrigated radiofrequency ablation catheter. Blood pressure (BP) measurements, blood sampling assays and renal angiography were performed at baseline, 30 min, one month and three months after ablation. RESULTS: During three months of follow-up, RDN caused a significant and uniform reduction in plasma level of renin, angiotensin II, and endothelin-1(ET-1), with the reduction of -5.7±6.8 (p=0.049), -19.4±19.3 (p=0.025), and -22.4±21 pg/ml (p=0.02) for plasma renin, -10.6±7.2 (p=0.004), -15.9±8.8 (p=0.001), and -15.2±9.6 pg/ml (p=0.003) for plasma angiotensin II, as well as -3.9±3 (p=0.007), -10.8±5 (p<0.001), and -14.6±6.1 pg/ml (p<0.001) for plasma ET-1. RDN utilizing a saline-irrigated catheter also caused a progressive and substantial BP reduction of -19±22/-8±13, -30±13/-13±14, and -36±20/-16±14 mm Hg (p=0.045, p<0.001, and p<0.002 for systolic BP; p=0.14, p=0.036, and p=0.014 for diastolic BP) without ablation-related complications. CONCLUSION: RDN substantially decreased BP and also significantly decreased the plasma levels of RAS and ET-1, which might be implicated in the mechanism of BP reduction by RDN.