糖克煎剂对2型糖尿病大鼠模型胰岛素抵抗影响的分子机制实验研究

【作者】 王东；

【导师】 姜良铎； 李敬林；

【作者基本信息】 北京中医药大学 ， 中医内科学， 2003， 博士

【摘要】 本论文分为理论研究、师承经验和实验研究三部分。第一部分理论研究，围绕本论文的实验研究内容，对胰岛素抵抗（IR）的中医药研究进展、脂代谢紊乱与2型糖尿病（DM）间的关系、肿瘤坏死因子α（TNF-α）与IR间的关系进行了综述。综述1，包括IR与2型糖尿病、高血压病和代谢综合征的中医病机和辨证分型之间的关系、中医药改善IR的研究进展及存在的问题；综述2，主要是关于肥胖与脂代谢紊乱、脂代谢紊乱与IR及脂代谢紊乱对胰岛β细胞脂毒性的研究进展；综述3，主要是关于TNF-α与IR的相关性、TNF-α致IR的作用机理及作用途径、以及针对TNF-α的IR的治疗的研究进展。第二部分师承经验，介绍了导师“从毒论治”的学术思想，导师提出的消渴的“脾虚致毒”的病机、以及从“脾虚致毒”论治消渴的观点。第三部分实验研究，采用尾静脉注射小剂量链脲佐菌素（STZ）加喂饲高热量饲料的方法，复制出2型糖尿病IR的大鼠模型；将实验大鼠分为正常对照组、模型组、中药糖克煎剂治疗组和胰岛素增敏剂罗格列酮治疗组；以胰岛素敏感指数（ISI）衡量糖克煎剂对IR的影响，并从糖克煎剂对脂代谢异常、对脂肪源性TNF-α、对胰岛素信号转导等方面的影响，探讨其作用机制。实验1，观测了各组实验鼠的血脂、血游离脂肪酸（FFA）和血一氧化氮（NO）水平；实验2，观测了各组实验鼠脂肪组织的TNF-α信使核糖核酸（mRNA）的表达水平、及葡萄糖转运体4（GLUT4）在骨骼肌组织中的表达情况；实验3，观测了各组实验鼠纯化的骨骼肌细胞胰岛素受体的酪氨酸激酶（TPK）活性及其β亚单位的酪氨酸磷酸化情况、以及各组实验鼠骨骼肌细胞的GLUT4的转位情况。结果表明，糖克煎剂可使2型糖尿病IR模型大鼠的脂质代谢异常得到改善，尤其是能够降低其血FFA和甘油三酯（TG）水平；能使模型大鼠的血NO水平升高，改善其血管内皮细胞功能；能使模型大鼠的脂肪组织TNF-α的mRNA表达水平降低；能使模型大鼠骨骼肌细胞胰岛素受体的TPK活性提高、并使其β亚单位的酪氨酸磷酸化增加；能使模型大鼠骨骼肌细胞的GLUT4的转位增加，但对GLUT4的蛋白含量可能无影响。通过以上作用，糖克煎剂可使2型糖尿病IR的大鼠模型的IR得到改善。更多还原

【Abstract】 This paper is composed of three parts.They are theoretical study,inherited experiences from tutor,and experimental study.The first part of theoretical study is consisted of three reviews which are related to the contents of experimental study, including the state of study on insulin resistance of traditional Chinese medicine(TCM),the relationship between lipodystrophy and type two diabetes mellitus , the relationship between tumor necrosis factor α and insulin resistance.Review one includes the relationship between insulin resistance and the pathomechanism of TCM or pattern identification which belongs to type two diabetes mellitus,hypertension and metabolic syndrome and the progress and problem of research on the improvement of insulin resistance by TCM. Review two is mainly about the progress of research on obesity and lipodystrophy, lipodystrophy and insulin resistance,the toxicity which caused by lipodystrophy on pancreatic β cells. Review three is mainly about the progress of research on the relativity of tumor necrosis factor α and insulin resistance,the mechanism or the pathway or the treatment of insulin resistance which caused by tumor necrosis factor α.The second part of inherited experiences from tutor discusses the academic theory of the toxin of tutor,viewpoint of tutor that the toxin which is caused by vacuity of Pi is the pathomechanism and principle of treament of Xiaoke disease.The third part of experimental study used method of injection a low dose of strepozotocin through vein of rat’s tail followed by a high caloric diet to duplicate rat model of insulin resistance of type two diabetes mellitus successfully and divided experimental rats into the control group,model group,TangKe decoction group and rosiglitazone group,measured the influence of TangKe decoction on insulin resistance by insulin-sensitivity index,explored the mechanism from the influences of TangKe decoction on lipodystrophy, tumor necrosis factor α which was produced by lipid and insulin signal transduction.Experiment one detected the blood lipid content,blood free fatty acid content and blood nitric oxide content of experimental rats.Experiment two detected tumor necrosis factor α expression in adipose tissue of experimental rats and expression level of glucose transporter 4 in skeletal muscule of experimental rats. Experiment three detected the protein tyrosine kinase activity of insulin receptor which was purified of skeletal muscule cell and the tyrosine phosphorylation degree of insulin receptor β subunit of experimental rats,observed glucose transporter 4 translocation of skeletal muscule cell of experimental rats.The result showed that TangKe decoction could increase the insulin sensitivity of rat model of insulin resistance of type two diabetes mellitus by improving its lipodystrophy,especially decreasing its levels of blood free fatty acid and blood triglyceride,increasing its level of blood nitric oxide and improving its vascular endothelium cell function,decreasing level of tumor necrosis factor α expression in adipose tissue, increasing its protein tyrosine kinase activity of insulin receptor which was purified of skeletal muscule cell<WP=9>and its tyrosine phosphorylation degree of insulin receptor β subunit,increasing its glucose transporter 4 translocation of skeletal muscule cell,but the protein content of glucose transporter 4 of skeletal muscule cell was unchanged probably.更多还原