肾动脉外膜消融对自发性高血压大鼠左室重构的影响

Effect of renal adventitia artery ablation on left ventricular remodeling in spontaneously hypertensive rats

目的探讨肾动脉外膜消融对自发性高血压大鼠左室重构的影响。方法雄性16周龄自发性高血压大鼠25只按随机数字法分为肾动脉外膜射频消融组(消融组,n=13)和假手术组(假手术组,n=12)。采用自制的射频消融仪行双侧行肾动脉外膜行环状消融。结果肾动脉外膜消融后,自发性高血压大鼠血压降至正常血压水平,与术前相比,差异有统计学意义[(127.9±13.0)mm Hg vs(165.0±6.7)mm Hg,P<0.01)。消融组术后心率逐步降低,术后3周下降最为显著,与术前相比差异有统计学意义[(332.5±26.3)次/min vs(392.5±34.1)次/min,P<0.01]。与术前相比,消融组术后3周时左室后壁厚度(LVPM)明显减少[(1.89±0.23)mm vs(2.23±0.25)mm,P<0.01];与假手术组相比,术后3周消融组LVPM显著减少[(1.89±0.23)mm vs(2.24±0.21)mm,P<0.01]。与假手术组相比,消融组肾素活性显著降低[(39.1±9.2)μg/(L·h)vs(20.8±8.8)μg/(L·h),P<0.01]。与假手术组相比,消融组心肌组织去甲肾上腺素水平显著降低[(217.3±36.4)ng/g vs(153.1±27.4)ng/g,P<0.05),消融组心肌组织肾上腺素水平显著降低[(113.5±28.3)ng/g vs(76.3±24.1)ng/g,P<0.05];Masson染色可见消融组心脏心肌间质纤维明显减少,心脏胶原容积分数(CVF)显著降低[(8.59±0.78)%vs(10.73±0.86)%,P<0.05]。血管紧张素1(ACE1)免疫组化染色显示消融组心肌组织ACE1生成减少,而ACE2生成增多。结论肾动脉外膜消融能逆转左室肥厚,改善左室重构,交感和肾素-血管紧张素-醛固酮系统(RAAS)系统的抑制可能是改善心肌重构的主要原因。

Objective To investigate the effect of renal adventitia artery ablation on left ventricular remodeling in spontaneously hypertensive rats （SHR）. Methods 25 spontaneously hypertensive male rats of 16 weeks were randomly divided into two groups： renal adventitia artery ablation group （RAAA Group, n=13） and Sham Operation Group （n=12）. Selfmade radiofrequency device was used for circumferential ablation on the renal artery adventitia. Results After renal adventitia artery ablation （RAAA）, the blood pressure of the SHRs dropped to normal level, and there was statistical difference compared with that before operation [（127.9± 13.0） mmHg vs （165.0±6.7） mmHg, P〈0.01]. The heart rate of the SHRs in RAAA Group was gradually decreased, and had the most significant decrease at the third week after operation, and there was statistical difference compared with that before operation [（332.5±26.3） bpm vs （392.5±34.1） bpm, P〈0.01）. Compared to that before operation, the left ventrieular posterior wall thickness （LVPM） in RAAA Group was significantly reduced about three weeks after operation [（1.89±0.23）mm vs （2.23±0.25） mm, P〈0.01]; compared with Sham Operation Group, LVPM in RAAA Group was also significantly decreased [（1.89±0.23） mm vs （2.24±0.21） mm, P〈0.01]. Compared with Sham Operation Group, the renin activity in RAAA Group was significantly reduced [（39.1±9.2） lig/（L.h） vs （20.8±8.8） μg/（L·h）, P〈0.01], the norepinephrine level of myocardial tissues in RAAA Group was significantly reduced [（217.3±36.4） ng/g vs （153.1±27.4） ng/g, P〈0.05], and the adrenaline level of myocardial tissues in RAAA Group was significantly decreased [（113.5 ± 28.3） ng/g vs （76.3±24.1） ng/g, P〈0.05]; Masson staining showed that myocardial interstitial fibrosis in RAAA Group was significantly reduced, and the heart CVF in RAAA Group was significantly decreased [（8.59±0.78）% vs （10.73± 0.86）%, P〈0.05]. ACE1 immunohistochemical staining showed a decrease of ACE1 but an increase of ACE2 in the myocardial tissue in RAAA Group. Conclusion Renal adventitia artery ablation can effectively reverse left ventricular hypertrophy and improve left ventricular remodeling in spontaneously hypertensive rats. The inhibition of sympathetic and RAAS system may be the main reason for the improvement of myocardial remodeling.