Renal sympathetic denervation attenuates left ventricle hypertrophy in spontaneously hypertensive rats by suppressing the Raf/MEK/ERK signaling pathway

Abstract

ABSTRACT Objective To explore the effect of renal sympathetic denervation (RSD) on left ventricle hypertrophy and the Raf/MEK/ERK signaling pathway in spontaneously hypertensive rats (SHRs). Methods SHRs were divided into SHR, SHR + Sham, SHR + RSD and SHR + U0126 groups, with WKY rats as the baseline controls. The blood pressure of rats was observed, while myocardial fibrosis was evaluated through Masson staining. Thereafter, real-time quantitative polymerase chain reaction (qRT-PCR) was carried out to determine the levels of myocardial-hypertrophy-related markers, and Western blotting was used to measure the activity of the Raf/MEK/ERK signaling pathway. Results In comparison with the WKY group, significant increases were observed in the systolic pressure and diastolic pressure of rats from the other four groups at different time points after surgery. In addition, rats in these groups had obvious increases in LVMI, renal NE and IVSd and decreases in LVEDd, LVEF and LVFS. In addition, the CVF of myocardial tissues was increased, with the upregulation of ANP, BNP and β-MHC and the downregulation of α-MHC. For the activity of the Raf/MEK/ERK signaling pathway, the levels of p-Raf/Raf, p-MEK/MEK and p-ERK1/2/ERK1/2 were all remarkably elevated (all P < .05). Further comparison with the SHR group showed that the above indexes in the rats were significantly improved in the RSD group and SHR + U0126 group (all P < .05). Conclusion RSD may decrease blood pressure, mitigate hypertension-induced left ventricle hypertrophy and improve cardiac function efficiently in SHRs via the suppression of the Raf/MEK/ERK signaling pathway.