目的:研究银杏叶提取物(EGB)对肿瘤坏死因子-α(TNF-α)诱导的牛主动脉内皮细胞(BAECs)血凝素样氧化低密度脂蛋白受体-1(LOX-1)表达的影响及其机制。方法:分离培养BAECs,应用TNF-α诱导BAECs表达LOX-1,给予EGB刺激,采用RT-PCR以及W estern b lotting的方法检测BAECs LOX-1表达的改变,同时用W estern b lotting检测内皮型一氧化氮合酶(eNOS)蛋白表达的变化,检测细胞培养液中亚硝酸盐(NO2-/NO3-)的含量。结果:TNF-α显著上调LOX-1的表达(P<0.05),EGB显著抑制TNF-α诱导的LOX-1的表达(P<0.05),而一氧化氮合酶抑制剂可显著抑制EGB的效应(P<0.05);TNF-α显著下调eNOS的表达(P<0.05),EGB显著促进eNOS蛋白的表达(P<0.05);TNF-α明显降低亚硝酸盐(NO2-/NO3-)的含量(P<0.05),EGB显著抑制TNF-α诱导的亚硝酸盐(NO2-/NO3-)含量的降低(P<0.05)。结论:EGB显著抑制TNF-α诱导的LOX-1的表达,其作用由EGB上调的NO介导。
This study investigated the effects of telmisartan on insulin resistance in high-fat diet-treated rats and the possible mechanism.A total of 40 male Sprague-Dawley rats enrolled in the study were divided into 4 groups at random：ND group（n=10） and HD group（n=10）,in which the rats were given a normal chow diet or a high-fat diet for 20 weeks following a one-week adaptation;ND＋telmisartan（n=10） group and HD＋telmisartan group（n=10）,in which the rats were initially administered in the same way as the ND or HD group,and then they were orally gavaged with telmisartan（5 mg/kg daily） additionally for 5 weeks.Related inflammatory factors were measured by ELISA.Monocyte chemotactic protein 1（MCP-1）,phosphorylated JNK and IκB-α expressions in both adipose and liver were detected by Western blotting.CRP and angiotensin Ⅱ receptor 1（AT1） mRNA expressions in both adipose and liver were determined by RT-PCR.The results showed that telmisartan administration in vivo reversed insulin resistance as evidenced by a decrease in plasma fasting glucose levels,plasma fasting insulin levels and homeostasis model of assessment-insulin resistance（HOMA-IR）.Furthermore,telmisartan administration significantly reduced serum CRP,TNF-α and IL-1β levels,and elevated serum IL-10 levels.It was also found to hamper the high-fat diet-induced increase in CRP mRNA,AT1 mRNA and MCP-1,and decrease in IκB-α in both adipose and liver.It was concluded that telmisartan administration in vivo may improve insulin resistance through attenuated inflammatory response pathways.
