O07 RENAL DENERVATION IMPROVES RIGHT VENTRICULAR FUNCTION, RESTORES MYOCARDIAL NOREPINEPHRINE LEVELS AND REVERSES VENTRICULAR SPECIFICITY OF SELECTED MARKERS IN HYPERTENSIVE RATS WITH HEART FAILURE INDUCED BY VOLUME OVERLOAD

Abstract

Background and objective: Despite the known anti-hypertensive effect of renal denervation (RDN), its influence on the cardiac function, particularly of the right ventricle (RV) and the cardiac sympathetic nervous system in heart failure (HF) is poorly understood. This study aimed to investigate the effect of RDN on RV function, myocardial norepinephrine (NE), and left versus right ventricular (LV/RV) dominance of HF markers in HF induced by aorto-caval fistula (ACF). Methods: ACF was created in hypertensive Ren-2 transgenic rats. RDN was performed by phenol application. Cardiac function was measured by echocardiography and pressure-volume analysis. NE levels were measured using an ELISA kit, protein expression was assessed by western blotting, gene expression by TaqMan PCR assay, and ROS by Amplex Red assay. Results: RDN in ACF rats decreased RV hypertrophy and dilatation, decreased RV end-systolic pressure and end-diastolic pressure, improved RV function (Ees +45%, FAC +20%), decreased HF gene markers Nppa, Tgm2, Myh7/6 ratio, and increased SOD2 protein expression. RDN decreased plasmatic NE levels, increased NE in RV, and decreased monoamine oxidase (MAO-A) in RV. NE levels and SOD2 were more dominant in RV than LV in control (sham/intact) rats and ACF changed their specificity towards RV dominance, while RDN had no effect in these parameters in ACF on ventricular specificity. In sham/intact rats dominant for LV were hemodynamic parameters Ees, EDPVR, and molecular markers Mao-a, ROS production by MAO-A, Nppa, Myh7, Myh7/6 ratio, Tgm2, Uchl1, and Beta1/Chrm2 ratio. ACF changed the dominance of these selected markers from LV to RV. Interestingly, RDN reversed dominance back towards LV in gene markers Mao-a, Nppa, Myh7, Tgm2, Uchl1, and Beta1/Chrm2 ratio. Conclusions: RDN decreased RV ESP and EDP, improved RV systolic function, restored NE levels, decreased RV gene expression of selected HF markers, and reversed their RV/LV dominance, probably by reduction of central sympathetic nerve drive and alternations of the cardiac sympathetic nervous system.