Effects of renal sympathetic denervation on long-term hypertension and cardiac remodeling in rabbits

AIM To observe the effects of renal sympathetic denervation (RSD) on long-term hypertension and cardiac remodeling. METHODS We established rabbit models of pressure overload hypertension by abdominal aortic constriction. After 2 months, abdominal RSD was carried out with radiofrequency ablation catheter. Two months after RSD, blood pressure values were measured by carotid artery intubation. For evaluation of the cardiac remodeling, left ventricular myocardial index was measured by weighing and calculating, ventricular wall thickness was measured by cardiac uhrasonography and myocardial fibrosis index was measured by Sirius scarlet staining method. Changes of NE, AVP, Ang II and Ald were also detected by ELISA. RESULTS Two months after RSD, blood pressure in hypertension+ablation group was lower than in hypertension group (P<0.05), but no significant difference was observed between control+ablation group and control group. Left ventricular posterior wall thickness (LVPWT), interventricular septum thickness (IVST) and left ventricular mass index (LVMI) increased significantly in hypertension group and control group (P<0.05). However, these values declined after ablation. Measurement of collagen content found that myocardial collagen volume fraction (CVF) was elevated in the hypertensive group but it also decreased after ablation, indicating that the level of cardiac remodeling was reduced. NE, Ang II, Ald and AVP in the hypertensive group were significantly higher (P<0.05) but NE and AVP decreased in hypertension+ablation group (P<0.05) after RSD. No significant difference was observed in Ald and Ang II. CONCLUSION RSD can reduce blood pressure caused by pressure-overload and can also reduce cardiac hypertrophy and cardiac fibrosis. The effects of RSD on long-term hypertension and cardiac remodeling may result from reducing the sympathetic ganglion of renal arteries.