【作者】 兰玲； 郭灿灿； 徐梦阳； 李梦莹； 贾航； 李修岭； 丁松泽； 张炳勇； 于静；

【机构】 河南省人民医院消化内科郑州大学人民医院； 锦州医科大学河南省人民医院规培基地； 河南大学河南省人民医院；

【摘要】 目的研究慢性心理应激对大鼠肝脏损伤和肝纤维化发展的促进作用,初步探讨其作用机制。方法 60只SD大鼠随机分为6组,分别为正常组、橄榄油组(肝纤维化阴性对照)、肝纤维化组、心理应激组、橄榄油+心理应激组和肝纤维化+心理应激组。给予大鼠40%四氯化碳皮下注射8周建立肝纤维化模型,皮下注射橄榄油作为阴性对照。造模第5周起采用慢性不可预知性应激方法持续4周制备慢性心理应激模型。造模第8周末处死大鼠,腹腔动脉取血,血液生化法检测肝功能和凝血功能;门静脉取血,偶氮显色法鲎试验检测脂多糖(lipopolysaccharide,LPS)水平;取肝脏组织,HE染色法检测肝组织病理损伤;Masson染色法检测肝组织胶原沉积情况,并用半定量分期评分法评价肝纤维化程度;免疫组化法检测肝组织4型Toll样受体(Toll-like receptor 4,TLR4)蛋白表达,并计算阳性染色累积光密度(integral optical density,IOD),对TLR4蛋白表达行相对定量。结果慢性心理应激大鼠的肝组织出现肝细胞变性坏死和炎症细胞浸润,并进一步加重肝纤维化大鼠的肝细胞坏死、炎症和纤维增生。肝纤维化大鼠在慢性心理应激的作用下,肝组织胶原纤维大量沉积,部分可见纤维间隔形成,肝纤维化分期评分较肝纤维化组进一步增高,但统计学差异不明显(P>0.05)。慢性心理应激大鼠血ALT、AST水平升高,PT%水平下降,尤其AST、PT%变化明显,同正常大鼠相比有统计学差异(P<0.05);肝纤维化大鼠在慢性心理应激作用下,ALT、AST、TBIL、PT和PT%均显著异常,同肝纤维化组大鼠相比,虽无明显统计学差异(P>0.05),但5项指标均呈现进一步恶化趋势。心理应激组、肝纤维化组和肝纤维化+心理应激组大鼠的门静脉血LPS水平依次呈梯度上升(P<0.05),肝组织TLR4蛋白表达(平均IOD值)也依次逐步增强(P<0.05)。结论慢性心理应激可作为独立影响因素导致大鼠肝脏损伤,并作为潜在加重因素促进肝纤维化发展,其作用机制可能与门静脉血LPS通过肝内LPS-TLR4信号转导通路影响肝脏有关。更多还原

【Abstract】 Aim To study the effect of chronic psychological stress on liver injury and liver fibrosis in rats,and preliminarily discuss the mechanisms.Methods Sixty SD rats were randomly divided into 6 groups:normal group,olive oil group(negative control of liver fibrosis),liver fibrosis group,psychological stress group,olive oil plus psychological stress group and liver fibrosis plus psychological stress group.The liver-fibrosis rat models were induced with 40% CC14 subcutaneous injection for 8 weeks,and olive oil was injected subcutaneously as negative control.From the 5 th week of modeling,the chronic unpredictable stress methods were used o prepare the chronic psychological stress models for 4 weeks.After 8 weeks of modeling,rats were killed.Blood was collected from the abdominal artery and portal vein for liver function and coagulation function detected by blood biochemical method and lipopolysaccharide(LPS) level detected by azochromogenic limulus test,respectively.The pathological damages of liver tissue were detected by HE staining.The collagen depositions of liver tissue were detected by Masson staining,and the degrees of liver fibrosis were evaluated by semi-quantitative staging scoring method.The protein expressions of Toll-like receptor type 4(TLR4) in liver tissue were detected by immunohistochemical method and quantified relatively by integrated optical density(IOD) of positive staining.Results Necrosis of liver cells and infiltration of inflammatory cells occured in liver tissues of rats with chronic psychological stress,which were further aggravated in liver-fibrosis rats with chronic psychological stress,even collagen deposition and fibrogenesis were observed.The staging score of liver fibrosis in liver-fibrosis rats with chronic psychological stress was further increased,compared with that in liver-fibrosis rats without stess although the statistical difference was not significant(P> 0.05).The levels of ALT and AST increased and level of PT% decreased in rats with chronic psychological stress,especially there were statistical differences in AST and PT%,compared with normal rats(P <0.05).Compared with rats with liver fibrosis,the levels of ALT,AST,TBIL,PT and PT% showed deteriorating in liver-fibrosis rats with chronic psychological stress,although there was no significant statistical difference(P> 0.05).The levels of LPS in portal vein blood and protein expressions of TLR4 in liver tissue of rats in psychological stress group,liver fibrosis group and liver fibrosis plus psychological stress group were elevated gradually(P <0.05).Conclusions Chronic psychological stress is an independent factor inducing liver injury,and also may be a potential aggravating factor promoting the development of liver fibrosis in rats.The mechanism may be related to the effect of LPS in portal vein blood on liver through LPS-TLR4 signal transduction pathway in liver.更多还原