Chinese Medicine Glucose Tolerance Kang Intervention Kkay Mice Insulin Resistance Signal Transduction Mechanism Of Action

Objective:To study the effection of Tangnai-Kang concoction for insulin resistance and Insulin signal-transduction pathway in spontaneous diabetic animal model KKAy mouse and 3T3-L1 adipocytes,then explaining the mechanism of it.Methods:In vivo,Specific pathogen free(SPF)KKAy mice 40 were divided randomly according to plasma glucose level into Models,TNK-low dosage,TNK-high dosage,Pioglitazone and normal C57BL/6J mice(normal control group).Each group was tested randomly plasma glucodelevel every week.60 days later,all animals were tested Fasting plasma glucose(FPG),Fasting insulin level for caculating Insulin Sensitivity Index(ISI),Total Cholesterol(TC),Total triacylglycerol(TG),High-density Lipoprotein Cholesterol (HDL-C),Low- density Lipoprotein Cholesterol(LDL-C),Floating fatty acid(FFA),Tumor necrosis factor-a(TNF-a)and dying islet by HE.At the end,tested the muscle and adipose expression of PI3-K and GluT4 mRNA by reverse transcriptase PCR(RT-PCR),tested the expression of GSK 3βprotein level and PKB/AktlαSer 473 phosphorating level.In vitro, 3T3-L1 preadipocytes were cultured in vitro and differentiated into the matured adipocytes, dyed oil red "O" to authenticate.Then using dexamethasone and isulin induced insulin resistance in 3T3-L1 adipocyte.Divied cells into seven groups,such as Models,TNK-low dosage(4%serum),TNK-middle dosage(8%serum),TNK-high dosage(12%serum),Rosiglitazone dosage(8%serum),blank serum dosage and normal control group(3T3-L1 adipocytes).Treated the cells 48h,then extracted the total RNA and protein.At the end,tested the expression of InsR mRNA,IRS-1,PI-3K,GSK-3 protein and GluT-4 mRNA by reverse transcriptase PCR(RT-PCR)and Western blot.Results:In vivo,compared with Model groups,FPG,TNF-a levels were all decreased significantly(p＜0.05);the expression of PI3-K and GluT4 mRNA were all up-regulated(p＜0.05 or p＜0.01);and PKB/Akt1αSer 473 phosphorating level were up-regulated at some degree(p＜0.05);the recipe could protectedβ-cells in some degree and postpontedβ-cells failure in islet,displayed decreasing tendency to the expression of GSK 3βprotein level and plasma lipocy and FFA levels.In vitro,compared with Model groups,the expression of everyone were upregulated in some degree following the serum concentration of Tangnai-Kang Compound.such as InsR and GluT-4 mRNA,IRS-1 and PI3-K p85 protein level, the expression of GSK-3βprotein level were down-regulated.The effecting of Rosiglitazone dosage group were similar with TNK-high dosage or TNK-middle dosage.Conclusion:Tang-nai Kang Concoction have the effection of improving the insulin resistance and protecting the isletβcells function,prevented the T2DM development,which may realized through these links as follows:①Recovery the abnormal of insulin signal-transduction,controlled the goal proteins or genes expression level,increasing the activity of the goal points in insulin signal-transduction pathway for which decreasing the FPG,Fins levels and so on.②Through decreasing the TNF-αlevel to relief the interference factors on insulin signal-transduction pathwy.On the other hand,the mechanism of the serum containing Tangnai-Kang Compound improving insulin resistance might be up/down-regulated the expression of key points in post-receptor of insulin signal-transduetion roads,so increased GluT-4 translocation.