Effects of renal sympathetic denervation on post-myocardial infarction cardiac remodeling in rats.

Xiongwen Chen,Jialu Hu,Ling Zhang,Yan Yan,Asiyeguli Aini,Qina Zhou,Conway Niu,Yuemei Hou,Meng Ji,Tao Jiang

doi:10.1371/journal.pone.0045986

Abstract

ObjectiveTo investigate the therapeutic effects of renal denervation (RD) on post- myocardial infarction (MI) cardiac remodeling in rats, the most optimal time for intervention and the sustainability of these effects.MethodsOne hundred SPF male Wistar rats were randomly assigned to N group (Normal, n = 10), MI group(MI, n = 20),RD group (RD, n = 10), RD3+MI (MI three days after RD, n = 20), MI1+RD (RD one day after MI, n = 20), MI7+RD (RD seven days after MI, n = 20). MI was produced through thoracotomic ligation of the anterior descending artery. RD was performed through laparotomic stripping of the renal arteriovenous adventitial sympathetic nerve. Left ventricular function, hemodynamics, plasma BNP, urine volume, urine sodium excretion and other indicators were measured four weeks after MI.Results(1) The left ventricular function of the MI group significantly declined (EF<40%), plasma BNP was elevated, urine output was significantly reduced, and 24-hour urine sodium excretion was significantly reduced. (2) Denervation can be achieved by surgically stripping the arteriovenous adventitia, approximately 3 mm from the abdominal aorta. (3) In rats with RD3+MI, MI1+RD and MI7+RD, compared with MI rats respectively, the LVEF was significantly improved (75±8.4%,69±3.8%,73±5.5%), hemodynamic indicators were significantly improved, plasma BNP was significantly decreased, and the urine output was significantly increased (21.3±5 ml,23.8±5.4 ml,25.2±8.7 ml). However, the urinary sodium excretion also increased but without significant difference.ConclusionsRD has preventive and therapeutic effects on post-MI cardiac remodeling.These effects can be sustained for at least four weeks, but there were no significant differences between denervation procedures performed at different times in the course of illness. Cardiac function, hemodynamics, urine volume and urine sodium excretion in normal rats were not affected by RD.

Highlights

Acute coronary occlusion results in the loss of myocardial tissue, the inhibition of myocardial function, and low blood pressure
renal denervation (RD) has preventive and therapeutic effects on post-myocardial infarction (MI) cardiac remodeling.These effects can be sustained for at least four weeks, but there were no significant differences between denervation procedures performed at different times in the course of illness
Hemodynamics, urine volume and urine sodium excretion in normal rats were not affected by RD

Summary

Introduction

Acute coronary occlusion results in the loss of myocardial tissue, the inhibition of myocardial function, and low blood pressure This leads to the activation of a series of neurohormonal factors, such as the baroreceptor-mediated sympathetic nervous system, the renin-angiotensin-aldosterone system (RAAS), endothelin, and tumor necrosis factor, which increases the heart rate, myocardial contractility, vasoconstriction, and fluid retention to help maintain hemodynamic stability. In this case, these intended mechanisms for short-term maintenance of blood pressure caused sustained activation, and will lead to left ventricular remodeling and deterioration of left ventricular function. We hope better animal research would confirm the efficacy of RD intervention in MI-induced cardiac remodeling, and we want to know the optimal time for performing RD and the sustainability of these effects

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Conclusion