Effects Of Ecdysterone On Early Stage Diabetic Nephropathy In STZ-induced Diabetic Rats

Objective:To investigate the influence of ecdysterone on early stage diabetic nephropathy in STZ-induced diabetic rats and approach its potential mechanism of action.Methods:①Reproduction of animal model: All experimental 80 SD rats were randomly divided into the animal reproductive group(n=70) and the negtive control group(N group)(n=10).The animal reproductive group was injected intraperitoneally with streptozotion (STZ,25 mg/kg),while the control group was injected with mitte tales doses of citric acid buffer solution.At 1 week after STZ.randomly selecting 48 rats whose FBG between 16.7mmol/L to 23.9mmol/L were brought into the following experiment.②Grouping:Diabetic rats were randomly divided into 4 groups.The first group was administered as controls group(D group,n=12), the other three groups were treated with lotensin(10mg/kg/d)(L group,n=12), ecdysterone(10mg/kg/d)(S group,n=12),and ecdysterone(100mg/kg/d)(M group,n=12),respectively.Meanwhile,the N group was administered as negative control group.All rats were injected intragastrically to treat 6 weeks.③The detection of biochemistry index(blood and urine samples):Results were evaluated by measurement of BUN,SCr,TP,Alb,concentration of urinary Alb and urinary Cr,and by computing the urinary albumin/urine creatinine(ACR).④Kidney pathology:HE staining was used to find pathological changes in kidney;Immunohistochemistry was used to test the expression of CTGF and ColⅣin kidney;ELISA was used to detect the contents of the NOS,ANGII, SOD and MDA in nephridial tissue.⑤Method of statistical analysis:Data were expressed as average±standard deviation.SPSS 13.0 was used for one-way analysis of variance with several group,we considered P values sequentiae 0.05 to be statistical significance.Results:①The change of body mass:After rats were treated 6 weeks,the body mass of N and M group rats increased significantly,while the body mass of D and L group rats decreased significantly Compared with M group(P＜0.05).②The result of TP,FBG and Alb:Compared with N groups there are no significant differences in TP and FBG among all diabetic groups,while in Alb is significant decreased(P＜0.01).③Comparison of renal function and ACR:BUN were increased in all diabetic groups,there are significant differences compared with N group(P＜0.05), Compared with N group,SCr is significant decreased in D and S group (P＜0.05),while the ACR is significantly increased(P＜0.01).In the diabetic groups,the ACR is significantly decreased compared with D group(P＜0.01).④The contents of the NOS,ANGII,SOD and MDA in nephridial tissue:The contents of the NOS is maximum in D group,compared with D group,of which in N,S,and M group are significantly decreased(P＜0.05);The contents of the ANGII is maximum in D group,compared with D group,of which in N and M group are significant difference(P＜0.05).The contents of the SOD is minimum in D group,compared with D group,of which in N,S,and M group are significantly increased(P＜0.05);while the contents of the MDA is maximum in D group,of which in N,S and M group are significant difference(P＜0.05), compared with D group.⑤Morphology of kidney:In gross appearance,the color of all diabetic kidneys are deeper than that of N group,and the cortex is thicker.On the high power lens HE staining section of kidney,all diabetic groups' glomcrulus cell and renal tubular cell are proliferation,hypertrophia, kytoplasm mult and karyotin darker on.These changes are lightest in L group, of which in S group are more heavy,while D group are the most heavy.⑥Electron micrographs showing the ultrastructure of rat glomerulus:The glomerular basement membrane of all diabetic groups was wrinkled,and thickened partly,with effacement of some visceral epithelial cell foot processes.These changes are lightest in L group,of which in S group are more heavy,while D group are the most heavy.⑦The expression of CTGF and ColⅣin kidney:There are no CTGF and ColⅣpositive expression cells in N group.While the positive expression cells are most in D group,brown and yellow are the darkest,compared with N group,and there has statistic difference(P＜0.01).Conclusion:①After rats were treated 6 weeks,the BUN was increased and the SCr was decreased and the body mass of diabetic rats was lightened,while the ecdysterone could progress the elevation of diabetic rats' body mass.②After rats were treated 6 weeks,the ACR of the diabetic rats was obviously increased,the ecdysterone could lower the ACR of the early stage DN of the rats.③Ecdysterone could lessen renal hypertropathy and injure of podocyte and the thicken of basement membrane of rats' the early stage DN.④The renal protection of ecdysterone could be relate to decreased content of MDA and NOS and to increase content of SOD in the early stage DN of rats.⑤The expressing of CTGF and ColⅣwas obviously up-regulation, which was mainly located in nephric tubule and collecting duct in the early stage DN of rats,while ecdysterone could down regulation the expressing of CTGF and ColⅣin kidney.