| Obejective:To study the protective effect of cordyceps polysaccharide (active ingredient of cordyceps sinensis) on type2diabetic rats with early renal damage, and try to explore the possible mechanism from the aspect of antioxidant effect.Methods:50SPF SD male rats devided into normal control group (NC) and module. Copying type2diabetic rat model by adopting the method of a high-fat diet+intraperitoneal injection of STZ.Devided models into:DM model group (DM), cordyceps polysaccharide group (CC), a-lipoic acid group (a-LA),CC+a-LA group (HE).Study the following three parts:Part1:Determinated the24h urine albumin, urine albumin to creatinine race, serum creatinine, blood urea nitrogen, pathological morphology of diabetic rats to evaluate the best breakthrough point and indicator of their early renal injuryPart2:By measuring the content of urine8-OHdG and UACR at different periods of both DM and CN, to analysis the relationship between oxidative stress injury and urine protein excretion of T2DM rats.Part3:Intervented models with different drugs according to group,10weeks later killed all. Determinated HbAlC,TG,TC,HDL-C,LDL-C.Take the kidney tissue to measure GSH, Mn-SOD, MDA,8-OHdG of each group.Tested the expression of p-JNK, cleaved caspase-3(the oxidative and apoptosis related signaling pathway).Results:Part1:The UACR elevated (P<0.05) at the4th week in T2DM progression and advanced into appearant albuminuria (P<0.05)at10th without BUN,Scr changes(P>0.05)or obvious glomerular sclerosis.Part2:The content of urine8-OHdG in models were significantly higher than the same period of NC group (P<0.05) as well as UACR. Also gradually increased with the extension of the disease course (P<0.05).Urine8-OHdG levels and UACR were positively correlated (P<0.01) in T2DM rat.Part3:HbAlC,TG,TC,HDL-C,LDL-C, SBP, DBP showed no difference in CC,a-LA, HE and DM groups (P>0.05).CC, a-LA, HE groups could reduce the kidney index (P<0.05) and UACR(P<0.01)of DM rats; Reduce8-OHdG (P<0.01),MDA (P<0.05) levels, enhance the Mn-SOD (P<0.01), GSH (P<0.01) vitality; Reduce p-JNK protein expression (p<0.05)and downstream caspase-3activation (p<0.01). CC, a-LA, HE groups had no difference in all above (P>0.05).Conclusion: Firstly,The10th weeks of T2DM duration can be thought of as boundary of early kidney damage and clinical phase in diabetic model.Secondly,The early oxidative damages associated with proteinuria in T2DM model, may participate in the DN startup.Thirdly,CC with the similar antiapoptotic effect as a-LA can reduce UACR,showing early renal protective effect of T2DM rat. |
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