2型糖尿病大鼠肝脏肿瘤坏死因子－α表达变化及丝胶的保护作用

摘要

Objective To study the change of tumor necrosis factor(TNF)-αexpression in liver of type 2 diabetes mellitus(T2DM) ratsandprotectiveactionsofsericin.Methods 48maleSDratswererandomlydividedintonormalcontrol,diabetesmodel,sericintreatment and positive control groups(n=12).The rats in model group were not given any more treatments,the rats in sericin treatment group were lav-aged with sericin (2.4 g・ kg-1・ d-1 ) for 35 d,the rats in positive control group were lavaged with metformin (55.33 mg・ kg-1・ d-1 ) for 35 d.SP immunohistochemical stain,Western blot and RT-PCR were used to detect TNF-αprotein and mRNA expressions in liver.Results Compared with those in normal control group,the TNF-αprotein and mRNA expressions in liver of rats in model group were increased obvi-ously (P<0.01).Compared with those in model group,the TNF-αprotein and mRNA expressions in liver of rats in sericin treatment and pos-itive control groups were decreased obviously ( P<0.01).Conclusions Sericin might improve insulin resistance by down regulating TNF-αexpression in liver.%目的：研究2型糖尿病大鼠肝脏肿瘤坏死因子（ TNF）－α表达的变化及丝胶的保护作用。方法雄性SD大鼠48只，随机分为正常对照组、模型组、丝胶治疗组及阳性对照组，每组12只。链脲佐菌素连续腹腔注射法制备2型糖尿病大鼠模型，成功后模型组大鼠不做处理，丝胶治疗组大鼠给予2．4 g・ kg－1・ d－1剂量的丝胶灌胃35 d，阳性对照组大鼠给予55．33 mg・ kg－1・ d－1剂量的二甲双胍灌胃35 d。采用SP免疫组化法、蛋白免疫印迹法和RT－PCR法检测各组大鼠肝脏TNF－α的表达情况。结果与正常对照组大鼠相比，TNF－α蛋白和mRNA在糖尿病模型组大鼠肝脏中均呈高表达（P＜0．01）；与模型组大鼠相比，TNF－α蛋白和mRNA在丝胶治疗组、阳性对照组大鼠肝脏中均呈低表达（P＜0．01）。结论丝胶可能通过下调肝脏TNF－α的表达改善胰岛素抵抗。