肝细胞生长因子联合缬沙坦对自发性高血压大鼠心肌纤维化的影响

Hepatocyte growth factor and valsartan synergistically attenuate myocardial fibrosis in spontaneously hypertensive rats

目的观察肝细胞生长因子(HGF)联合缬沙坦对自发性高血压大鼠(SHR)心肌纤维化的影响并探讨其机制。方法以雄性Wistar大鼠作正常对照组(N组,n=6)。30只雄性SHR随机分为5组(n=6):高血压对照组(P组);假手术组(sham组,实验开始时,开胸,在大鼠左室游离壁的5个点直接注入null-Ad5,0.1 ml,术后常规饲养4周);HGF组(H组,实验开始时,开胸,在大鼠左室游离壁的5个点直接注入5×109Pfu/ml Ad5-HGF,0.1 ml,术后常规饲养4周);缬沙坦组[V组,缬沙坦灌胃30 mg/(kg·d),治疗4周];HGF联合缬沙坦组[HV组,实验开始时,开胸,在大鼠左室游离壁的5个点直接注入5×109Pfu/ml Ad5-HGF,0.1ml,术后予以缬沙坦灌胃30 mg/(kg·d)×4周]。治疗前及治疗开始后每周测量一次尾动脉血压。治疗4周后,处死大鼠,用ELISA法测定心肌HGF、转化生长因子-β1(TGF-β1)和基质金属蛋白酶-1(MMP-1)的表达;Masson染色评价心肌胶原容积分数(CVF);免疫组化法评定心肌组织I型胶原(Collagen I)含量。结果治疗2周后,HV组和V组血压明显下降,随后维持较低水平(P<0.05);治疗4周后,检测心肌相关指标:CVF和Collagen I含量,以HV组降低最为明显(P<0.05),其次为H组、V组;HGF表达,以HV组、H组最高(P<0.05),其次为V组;TGF-β1的变化同CVF和Collagen I,而MMP-1以H组和HV组明显升高(P<0.05)。结论对于SHR,HGF联合缬沙坦对高血压引起的心肌纤维化的疗效优于单独用药,其机制可能为两者联用能更充分地抑制TGF-β轴,调节MMP-1的水平,从而进一步提高抗心肌纤维的疗效。

Objective To observe the effect of both hepatocyte growth factor and valsartan on myocardial fibrosis in spontaneously hypertensive rats. Methods Wistar rats as normal control （ N group, n = 6） ; spontaneously hypertensive rats （n = 30） were randomly assigned into five groups （n = 6） ： hypertension control（ P group） ; sham control （ sham group, at the begin of research, delivery of null-Ad5 ,0. 1 ml into the left ventricle wall at five different points by direct injection and then fed them normally next 4 weeks） ; HGF（ H group, at the begin of research, de- livery of 5 x 109 Pfu/ml Ads-HGF,0. 1 ml into the left ventricle wall at five different points by direct injection and then fed them normally next 4 weeks） ; valsartan[ V group, delivery of valsartan 30 mg/（ kg· d）by intragastric administration] ;both HGF and valsartan [ HV group, at the begin of research, delivery of 5× 10^9 Pfu/ml Ads-HGF, 0. 1 ml into the left ventricle wall at five different points by direct injection and then gave valsartan 30 mg/（ kg ·d） by intragastric administration for 4 weeks ]. Every group was taken tail blood pressure at the start of this study and every week during administration period. After 4 weeks treatment, the expression of HGF, TGF-β1 and MMP-1 in left ventricle were assessed by Enzyme-Linked Immunosorbent Assay（ ELISA）, myocardial collagen volume fraction （CVF） was evaluated by Masson collagen staining method, and Collagen I in left ventricle was observed by immu- nohistochemistry. Results The blood pressures of V group and HV group dramatically decreased within two weeks of medication and then leveled off（P 〈 0.05）. After 4 weeks of treatment, CVF and Collagen I in the groups re- ceiving treatment were all reduced, especially HV group （ P 〈 0.05 ） ; the level of HGF in left ventricle was the highest in HV group （ P 〈 0.05 ） , which followed by H group, V group, and the level of MMP-1 increased in these three groups as well, especially in H group and HV group, however, the concentration of TGF-β1 was on an opposite trend. Conclusion Hepatocyte growth factor and valsartan can synergistically attenuate myocardial fibrosis in spontaneously hypertensive rats, the effect of combination is better than each of them, which could intervene more comprehensively-could suppress the excessive expression of TGF-β1, adjust the level of MMP-1 more effectively and efficiently, which enhance the curative effect.