内源性硫化氢对二乙基二硫代氨基甲酸盐诱导的大鼠慢性胰腺纤维化的影响

Effect of endogenous hydrogen sulfide on pancreatic fibrosis induced by diethyldithiocarbamate in rats

目的探讨内源性硫化氢(hydrogensulfide,H2S)对二乙基二硫代氨基甲酸盐(diethyldithiocarbamate,DDC)诱导的大鼠胰腺纤维化模型的影响。方法健康雄性Wistar大鼠48只,随机分成对照组、模型组、Na HS组和PAG组,每组各12只。其中模型组间大鼠腹腔内注射10%DDC溶液(700 mg/kg),隔日1次,共注射15次;Na HS组于造模的同时再注射H2S供体硫氢化钠(sodium hydrosulfide,Na HS)(56μmol/L),1次/d;PAG组于造模的同时再注射DL-炔丙基甘氨酸(DL-propargylglycine,PAG)(45μmol/L),1次/d;对照组和模型组则注射同等体积的生理盐水,1次/d。实验后第30天,处死各组大鼠,留取动脉血和胰腺组织;采用H-E染色,在光学显微镜下观察胰腺组织学变化;采用Masson染色,测胶原纤维含量并进行病理学评分;采用ELISA法检测胰腺组织中Ⅰ型胶原、TGF-β1含量;采用Western印迹法检测胰腺组织中Smad7蛋白的表达,并检测血浆H2S含量。结果模型组、Na HS组和PAG组大鼠胰腺组织病理学评分、胶原纤维含量、Ⅰ型胶原和TGF-β1明显高于对照组(P<0.05),而模型组明显高于Na HS组(P<0.05),PAG组明显高于模型组、Na HS组(P<0.05)。对照组、模型组和PAG组血浆H2S含量明显低于Na HS组(P<0.05),模型组明显低于对照组(P<0.05),PAG组明显低于模型组(P<0.05)。模型组、Na HS组和PAG组胰腺组织中Smad7蛋白表达明显低于对照组(P<0.05),Na HS组、模型组明显高于PAG组(P<0.05),Na HS组明显高于模型组(P<0.05)。结论在DDC诱导的大鼠胰腺纤维化模型中,内源性H2S能够有效抑制实验性大鼠胰腺纤维化,其机制可能是通过TGF-β1/Smad信号通路上调胰腺组织中Smad7蛋白的表达及下调TGF-β1的表达。

Objective To investigate the effect of sodium hydrogen sulfide （NaHS） on pancreatic fibrosis induced by diethyldithiocarbamate （DDC）.Methods Forty-eight Wistar rats were randomized into four groups （12 per group）： normal control group, model group, NaHS group and PAG group.Pancreatic fibrosis was induced by intraperitoneal injection with 10% DDC （700mg/kg）;sodium hydrosulfide （56μmol/L） or DL-propargylglycine （45μmol/L） was intraperitoneally injected 1/d in rats of HaHS and PAG groups, respectively;an equal volume of saline was intraperitoneally injected in control and model groups.All animals were sacrificed on d30.The pancreas samples were harvested for the macroscopic and microscopic examinations.Collagen Ⅰ and TGF-β1 in pancreatic tissue were detected by ELISA method, Smad7 was determined by Western blotting, plasma H2S level was measured.Results Compared with the control group, the histological damage score, collagen area, the level of collagen Ⅰ and TGF-β1 were significant higher in model group, NaHS group and PAG group（ P 〈0.05）;those indicators in model group were significant higher than in NaHS group（ P 〈0.05）;those in PAG group were significant higher than in model group and NaHS groups（ P 〈0.05）.The expression of Smad7 was significant higher in control group than that in model group, NaHS group and PAG group（ P 〈0.05）;the expression of Smad7 in NaHS group was higher than that in model group and PAG group（ P 〈0.05）;the expression of Smad7 in model group was significant higher than that in PAG group（ P 〈0.05）.The level of serum H2S was significant higher in NaHS group than that in control group, model group and PAG group（ P 〈0.05）;the serum H2S level in control group was significant higher than that in model group（ P 〈0.05）;the serum H2S level in model group was significant higher than that in PAG group（ P 〈0.05）.Conclusion Hydrogen sulfide has a significant anti-fibrosis effect on pancreatic fibrosis induced by DDC in rats, which is possibly related to the up-regulation of the expression of Smad7 and down-regulation of the TGF-β1.