血管钠肽抑制肝纤维化的实验研究

Study of inhibitory effects of vasonatrin peptide on liver fibrosis

目的探讨人工合成的钠尿肽-血管钠肽(VNP)对肝纤维化的抑制作用。方法雄性Balb/c小鼠,随机分为玉米油对照组(对照组:腹腔注射玉米油1mL/kg,每周2次,持续12周),肝纤维化模型组(模型组:腹腔注射CCl41mL/kg,每周2次,持续12周,最后6周静脉注射生理盐水1mL/kg.d)和肝纤维化模型+VNP治疗组(VNP治疗组:腹腔注射CCl41mL/kg,每周2次,持续12周,最后6周静脉注射VNP50μg/kg.d)。于末次注射后3d取各组小鼠肝脏标本,观察肝脏病变程度和纤维化水平。体外培养鼠肝星状细胞株(HSC-T6),并加以不同浓度的VNP处理,分别采用[3H]-胸苷和[3H]-脯氨酸掺入的方法检测细胞DNA和胶原的合成水平。结果和对照组比较,模型组出现显著肝脏损伤和胶原沉积,而VNP治疗能明显减轻CCl4诱导的肝脏损伤和胶原沉积;对照组,模型组,VNP治疗组肝脏胶原浓度分别为(43.6±6.3)μg/mg,(93.5±7.2)μg/mg,(62.2±5.1)μg/mg,差异有统计学意义(P<0.05);VNP(10-7mol/L)处理后,HSC-T6的[3H]-胸苷和[3H]-脯氨酸掺入量分别较对照组减少了48.5%和43.7%(均P<0.05)。结论 VNP能抑制CCl4诱导的肝纤维化,该作用可能与其抑制肝星形细胞的增殖以及胶原合成有关。

Objective To investigate the effects of vasonatrin peptide（VNP）,a synthetic novel natriuretic peptide,on liver fibrosis. Methods Male Balb/c mice were randomized into corn oil control group（control group for short,protocol： corn oil 1 mL/kg ip.twice a week for 12 weeks）,liver fibrosis group（model group for short,protocol： CCl4 1 mL/kg ip.twice a week for 12 weeks,and saline 1 mL/kg iv.once daily for the last 6 weeks） and hepatic fibrosis＋VNP treatment group（VNP treatment group for short,protocol： CCl4 1 mL/kg twice a week for 12 weeks,and VNP 50 μg/kg iv.once daily for the last 6 weeks）.The liver samples were harvested from mice on the 3rd day of the last injection to evaluate the histopathological change and fibrotic level of the liver.The mouse hepatic stellate cell line（HSC-T6） was cultured in vitro and was exposed to VNP of different concentrations,and then the DNA and collagen synthesis of the cells were determined by -thymidine and -proline incorporation assay,respectively. Results The livers of the model group presented significant impairment and collagen accumulation compared with that of the control group.However,the hepatic impairment and collagen accumulation induced by CCl4 was effectively alleviated by treatment with VNP.Liver collagen concentration of control group,model group and VNP treatment group was（43.6±6.3） μg/mg,（93.5±7.2） μg/mg and（62.2±5.1） μg/mg,respectively,and the differences were statistically significant（P0.05）.The -thymidine and -proline incorporation rate of HSC-T6 after exposure to VNP（10-7 mol/L） was decreased by 48.5% and 43.7%,respectively（both P0.05）. Conclusions VNP has inhibitory effect on CCl4-induced liver fibrosis,which may probably be associated with its effect of inhibiting the proliferation and collagen production of hepatic stellate cells.