| Objective: As long as the increasing standard of living,the incidence of diabetes mellitus (DM) rises year after year. Diabetic nephropathy (DN) is the familiar microvascular complications of type 2 diabetes mellitus (T2DM),and it is also the major pathogeny and the main reason of type 1 diabetes mellitus (T1DM) patients'prematurity death. Including American,Australia,some countries in Europe and Singapore, DN is the first reason of end stage renal disease (ESRD). Integrin-linked kinase(ILK) is significantly expressed in renal cortex ,might be involved in diabetic renal injury. Statins not only can adjust adipose of the kidney protective function, but also has anti-inflammatory,immunoregulation negatively depending on tune adipose of the kidney protective function. The study reproduced T2DM rat model by feeding Sprague-Dawlay(SD)rats by high glucose,high fat diet and low dose of streptozotocin(STZ). Then the protein expression of the ILK in kidney of experimental rats were detected in order to discuss the association between ILK and DN. Furthermore, simvastatin were given to experimental rats to explain its mechanism of protective effects on DN.Methods: 10 of 50 SD rats were taken out randomly to be normal control rats (group A) and the rest were taken for test rats. The control rats were fed with general diet and the test rats were fed with high-sugar-fat diet. 4 weeks later, IR was induced in test group, then STZ 30 mg/kg was injected into abdominal cavity to destroy pancreas. At the end of 6 weeks, the rats whose fasting blood glucose (FBG) was greater than 7.8 mmol/L and insulin sensitivity decreased were considered as T2DM rats. T2DM rats were divided randomly into 2 groups: T2DM model rats (group B),T2DM model rats treated with simvastatin (group C). The experiment lasted for 14 weeks. At the end of 6 weeks, FBG, fasting insulin (FINS), insulin sensitivity index (ISI), serum creatinine(Scr), serum triglyceride (TG) and total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C) in different group rats were measured. 24 hours urine was collected by metabolic cage.Endogenous creatinine clearance rate(Ccr)and urinary albumin excretion rate (UAER) were respectively measured at the end of the experiment. The microstructure and ultrastructure of renal were observed with light and electron microscopes. Kidney specimens were prepared for HE-stained, PAS-stained and Masson-stained.The protein expression of ILK in renal was detected by immunohistochemical staining. The results were analyzed with computer image-analysis system and the integral optical density (IOD) counts of ILK were calculated. The percentage of renal fibrosis calculated by medical image analysis system. The data was dealt with SPSS 13.0.Results1 Various indexes after 6 weeks:2 weeks after STZ injection, FBG(12.87±1.00) mmol/L of test rats was higher than FBG(5.06±0.70) mmol/L of control rats.FINS 18.79(18.23, 19.29) mIU/L of test rats compared to FINS 18.35(17.95, 18.98) mIU/L of control rats was unstatistics distinction (P>0.05).ISI 0.0048(0.0045, 0.0053) of test rats was lower than ISI 0.0106(0.0103, 0.0112) of control rats (both P<0.01). Thus far, the T2DM rat model was accomplished.2 Various biochemical indexes after 14 weeks: When the experiment was finished, FBG in group A rats was (4.96±0.92) mmol/L,TG(0.67±0.21)mmol/L,TC(2.23±0.43)mmol/L,LDL-C(1.23±0.12)mmol/L,VLDL-C(0.36±0.08)mmol/L,HDL-C(0.89±0.06) mmol/L.FBG in group B rats was(13.15±1.18)mmol/L,TG(1.89±0.20)mmol/L,TC(3.23±0.28)mmol/L,LDL-C(2.32±0.12)mmol/L,VLDL-C(0.85±0.11)mmol/L .They were all higher than those in group A rats. HDL-C in group B was 0.37±0.08mmol/L and it was lower than that in group A rats. FBG in group C rats was 12.70±1.05mmol/L.Compared with FBG in group B, there was no significant difference. TG(1.33±0.26)mmol/L,TC(2.44±0.35)mmol/L,LDL-C(1.55±0.11)mmol/L and VLDL-C(0.57±0.10)mmol/L werr lower than those in group B. HDL-C in group C (0.56±0.10) mmol/L was higher than that in group B.3 Kidney weight/Body weight: The kidney weight/Body weight (8.96±1.08)in group B was higher than that in group A(3.59±0.29)(P<0.01). The kidney weight/Body weight (7.01±0.97)in group C was decreased (P<0.01),but it was also higher than that in group A (P<0.01).4 Urinary albumin: Compared with group A (0.03±0.21mg/24h), urinary albumin (1.37±0.05mg/24h) in group B increased significantly (p <0.01).Compared with group B, urinary albumin ( 0.66±0.02mg/24h) in group C significantly reduced, but still higher than that in group A (p <0.01).5 Urinary albumin:①BUN: Compared with group B (8.22±1.36 mmol / L) and group C (7.75±1.52mmol / L ) with group A (6.99±1.45 mmol / L), there was no significant difference among those groups in the level of change (p> 0.05).②Ccr : Compared with group B (62.59±10.45)μmol/L and group C (60.88±10.10)μmol/L with group A (60.50±6.02)μmol/L, there was no significant difference in the level of change (p> 0.05).③Ccr: Ccr in Group B (1.32±0.36ml/min) was significantly higher than that in group A (0.12±0.06ml/min) (p <0.01); Ccr in Group C (0.47±0.35ml/min) was lower than that in group B, but still higher than that in group A (p <0.01).6 Morphology: HE staining showed: that glomeruli shape regulation, renal glomerulus cell arrangement rule, basement membrane clear and regulation, Bomen's capsular space is evident in group A. Glomeruli cubic capacity augmentation and cell to increase obviously in group B. Affection to lighten slightly in group C, but still had the difference with group A. PAS staining showed that masculine unusual material increased in group B, basement membrane thickening widespread, collogen to raise. Affection to lighten slightly in group C, basement membrane thickening little, collogen to decrease. Masson staining showed that mesangial region basilaris substantia to increase obviously in group B. Electron microscope showed that glomeruli basement membrane uniformity, foot process to line up in order in group A. Endotheliocyte eumorphism; basement membrane diffuse thickening, foot process meromixis in group B rat. Degree to lighten in group C.7 The expression of ILK in renal cortex: The IOD (50.95±4.64) of ILK in group B rats was 8.1 times more than that(6.28±2.28)in group A rats. The IOD(21.40±5.53)of ILK in group C rats was 58% less than that in group B rats (P<0.01). Masson staining: B Group of renal fibrosis was 36%±3%, and this was correlated with ILK optical density (r=0.672, p <0.01).Conclusions1. There was the change of ILK protein expression in the diabetic nephropathy occurrence.2. Urine protein,renal function and kidney hypertrophia,fibrosis level was related with the ILK protein expression which had the promotion kidney to be hypertrophia and fibrosis function.3 Simvastatin may be reduce the urine protein excretion, cut down kidney hypertrophia and fibrosis level. The function of simvastatin related with reducing the ILK protein expression.and did not rely on the blood glucose changing. |
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