MODELING OF DIABETIC NEUROPATHY IN RATS IN THE EXPERIMENT

Abstract

Full Text

Purpose of the work was to reproduce the experimental model of diabetic neuropathy with long-term hyperglycemia provoked by the streptozotocin intoxication of rats. Materials and methods: experimental diabetes mellitus was modeled on 50 mature outbred male rats weighed 200-230 g by means of single intravenous injection of streptozotocin (Sigma, USA), soluted in 0.1 M citrate buffer with pH 4.5 at dose 45 mg/kg. Quantitative determination of the glucoses in blood was done on the 3rd day after the injection of cytotoxin and then every week in morning time, before feeding, during the whole term of the experiment with the help of glycometer Glukokard (Russia). The animals with the level of glucoses before feeding more than 17 mmol/l were used in the experiment. Once achieving the glycemia level on an empty stomach more than 20 mmol/l the animals were injected with an insulin of long-term action LantusSoloStar, France (percutaneously). In the course of the experiment with a break for 1 week we estimated the weight of all experimental animals. Every 4 weeks rats were placed for 24 hours into individual metabolic cameras fir urine sampling with the objective to investigate a daily excretion of albumin (colorimetric method with bromphenol blue Vital Diagnostics (Russia); determination of creatinine concentration of the blood serum (with further calculation of creatinine clearance) by means of Yaffe method with the use of Pliva-Lachema set (Czech Republic). After the termination of the 12-week experiment we determined the level of glycohemoglobin with the used of Фосфосорб (Fosfosorb) (Russia). We carried out the statistic processing with the use of Microsoft Excel 2007 editor and GraphPad Prism 5.0 program. Results: the glucoses level in the blood of rats with diabetes mellitus on the third day and during the whole tests relevantly exceeded the indices of intact animals (in 4.5 times at average (p<0.05)). The results obtained were affirmed statistically with a significant two times (p<0.05) increase of the level of glycosylated hemoglobin of rats with streptozotocin intoxication lasted for 3 months concerning the intact rats by the end of the test. The decrease of body weight by 20% in comparison with the original was encountered in rats with pathologies. Every 4 weeks we registered the relevant augmentation of the protein level in the urine of the animals with streptozotocin intoxication in comparison with the values of an intact group of rats (2.4 time at average (p<0.05)), which points at the affection of the glomerulose apparatus of the nephron of the diabetic genesis. Creatinine clearance of rats with diabetes mellitus increased in comparison with those of the intact animals (2.4 times - 1st month, 1.64 times - 2nd month, 2.06 times 3rd months), which can take place as the result of creatinine hyperfiltration, which takes place in the early phase of diabetic nephropathy. Conclusions: the results obtained give evidence about the fact that rats have the early exhibitions of diabetic nephropathy formed with long-term streptozotocin intoxication. The reproduced experimental model can be used for the profound pharmacological study of potential preventive drugs of diabetic nephropathy. The paper was supported with a grant of the Russian Scientific Fund (project no 14-25-00139).