OBJECTIVETo investigate the effect of renal sympathetic denervation on left ventricular hypertrophy and inflammatory factors in spontaneously hypertensive rats.

METHODSThirty six spontaneously hypertensive rats (SHR) were divided into 3 groups with 12 animals in each group: SHR control group,operation group and sham operation group. Bilateral renal sympathectomy or sham operation were performed in operation and sham groups,respectively; another 12 WKY rats served as normal controls. The blood pressure and body weight were examined weekly. The animals were sacrificed at w1 and w6, rat hearts were collected and left ventricular mass index (LVMI) was calculated. The expression of TLR4,TNF-α and IL-6 in heart tissue were detected by immunohistochemistry and Western blot.

RESULTSThe systolic blood pressure [(201.67 ± 11.09) mmHg compared with (140.0 ± 10.86)mmHg,P<0.05],diastolic blood pressure [(144.50 ± 10.48)mmHg compared with (78.50 ± 7.32)mmHg,P<0.05], LVMI (2.44 ± 0.05 compared with 1.93 ± 0.05,P<0.05),the expression of TLR4 (0.298 ± 0.004 compared with 0.126 ± 0.004, P<0.05), NF-κB (0.249 ± 0.006 compared with 0.195 ± 0.005, P<0.05),TNF-α(0.323 ± 0.004 compared with 0.146 ± 0.004,P <0.05), IL-6 (0.283 ± 0.005 compared with 0.207 ± 0.006, P<0.05) in SHR control group were significantly higher than those in WKY group. Compared to sham operation group,the systolic blood pressure (157.30 ± 9.35 compared with 197.30 ± 11.5, P<0.05),diastolic blood pressure (112.50 ± 6.25 compared with 146.80 ± 7.6, P<0.05),LVMI (2.32 ± 0.04 compared with 2.57 ± 0.09, P<0.05, TLR4 (0.198 ± 0.006 compared with 0.317 ± 0.008, P<0.05), NF-κB (0.208 ± 0.006 compared with 0.332 ± 0.007, P<0.05), TNF-α(0.27 ± 0.009 compared with 0.375 ± 0.004,P<0.05), IL-6 (0.218 ± 0.004 compared with 0.376 ± 0.009, P<0.05) in operation group were all decreased at w1 after sympathectomy. Six weeks after the operation,there were no significant differences in systolic blood pressure (197.50 ± 12.13 compared with 208.83 ± 10.23,P>0.05) and diastolic blood pressure (150.33 ± 7.74 compared with 151.50 ± 8.22, P>0.05) between denervated and sham-operated SHRs; however,the LVMI (2.46 ± 0.07 compared with 2.81 ± 0.05,P<0.05) and the expression of TLR4(0.301 ± 0.009 compared with 0.567 ± 0.006, P<0.05), NF-κB (0.251 ± 0.004 compared with 0.476 ± 0.009,P<0.05),TNF-α(0.324 ± 0.005 compared with 0.535 ± 0.006, P<0.05,IL-6 (0.285 ± 0.009 compared with 0.549 ± 0.007, P<0.05) in operation group were still significantly lower than those in sham operation group.

CONCLUSIONRenal sympathetic denervation can significantly delay the progression of LVH in SHR, which may associated with lowering blood pressure and decreasing expression of TLR4, NF-κB,TNF-α, IL-6 in myocardial tissue.