Study of the method used to induce the model of type 2 diabetic mellitus rat and the characteristic of the nephropathy

Abstract

Objective To discuss the feasibility of the method that can be used to induce the model of type 2 diabetic mellitus rat and explore the characteristic of the nephropathy.The rats were fed with the high sucrose,high fat and high energy feed for a long time and then it was injected with the low dose STZ.Methods 30 SD rats were selected and then it was randomly divided them into 2 groups,the control group (10 rats) and the model group (20 rats).The model group was fed with the high calorie feed forl0 weeks to induce insulin resistance and then the rats were induced to type 2 diabetes mellitus by injection of streptozocin (30 mg/kg).The rats of the model group were continually fed with the high calorie feed for 2 months.Before the end of this study,the 24-hours microalbuminuria,serum creatinine and blood urea nitrogen were detected and the periodic acid Schiff staining on the kidney were also measured.Results After the rats of the model group were established,the levels of the bodyweight,the cholesterol,the triglyceride and the insulin were [ (468.7 ± 8.8 ) g,( 1.92 ± 0.27 ) mmol/L,( 1.32 ± 0.34) mmol/L,(38.81 ± 5.39 ) mU/L ] respectively,all of them were higher than the levels in the normal group,which were [ (436.9 ± 7.4) g,(1.16 ±0.17)mmol/L,(0.8 ±0.18)mmo1/L,(21.43 ±4.19)mU/L],respectively( t =9.755,8.077,4.437,8.902,P ＜ 0.01 ).After injection of STZ for 2 weeks,the levels of the blood glucose,the insulin and the insulin resistance of the diabetes mellitus rats were [ ( 19.31 ± 1.55 ) mmol/L,( 31.31 ± 8.60) mU/L,(26.55 ± 6.33) ] respectively,it was higher than levels inf the normal group,which was[ (5.45 ±0.69) mmol/L,( 19.97 ± 3.26) mU/L,(4.82 ± 0.84) ] ( t =26.383,3.951,10.719,P ＜ 0.01 ).Before the end of this study,the levels of the blood glucose,insulin resistance,24-hours microalbuminuria,serum creatinine,blood urea nitrogen of the diabetes mellitus rats were [ ( 19.27 ± 1.97 ) mmol/L,( 16.70 ±7.51 ),(72.49 ± 8.53 ) mg/24 h,( 74.76 ± 8.38 ) μmol/L,( 19.09 ± 4.21 ) mmol/L],it was higher than the levels in the normal group,which were [ (5.62 ±0.65) mmol/L,(5.45 ± 1、33),( 15.26 ±2.20) mg/24 h,(40.81 ± 1.97) μmol/L,(9.87 ±2.13) mmol/L,t =20.961,4.657,20.623,12.495,6.352,P ＜0.01 ].And the pathological changes of the diabetes mellitus rats kidney tissues were the most serious through themethod of periodic acid-Schiff's staining (PAS).Conclusions The model of type 2 diabetic mellitus rat was constructed through the way of feeding the SD rats with high sucrose,high fat and high energy feed for a long time and low dose STZ.The diabetic mellitus rats had the symptom of drinking more,eating more and diuresis,and the character of this model had high levels of albuminuria,serum creatinine,blood urea nitrogen.The incrassated glomerular mesangium,the crescent-shaped focus and the glomerulosclerosis were also observed through the PAS. Key words: Diabetic nephropathies ; Models, animal ; Streptozocin/AD