The Study Of Protective Effect Of Selenite On Kindey Of Diabetic Nephropathy Rats

Background: With the raising of people's life level and the changing of people's life style, the rate of diabetic vascular complications is ascending year by year. Diabetic nephropathy is one of the diabetic microvascular complications, and it's incidence rate is rising in recent years, and it has become the prime cause of End Stage Renal Disease (ESRD). It is one of the serious complications and main death cause of Diabetes mellitus(DM) too. Once emerging persistent proteinuria, the disease should not be reverted, which would develop end stage renal disease eventually. The patients survive only depend on dialysis and vicariousness treatment. So it is important to interfere in earlier period of the disease for delaying the disease process.Selenium is one of the essential trace element of organism, and it consists in glutathione peroxidase.It's main function is cleaning organism endoperoxide and keeping up the integrity of membrane system.It is discovered that selenite can imitate insulin to decrease serum glucose and regulate metabolic process mediated by insulin. To supplement selenium for diabetic rats not only protect oxidative stress , but also prevent kindey injury. Simultaneously, it can improve glucose internal environment and the sensitivity of periphery tissue toward insulin. In diabetic nephropathy, selenium intervention effect and molecule mechanism is less reported in internal and overseas, so it is really worth studying. PART ONE THE EFFECT OF SELENITE ON BASIC CONDITIONS AND PATHOLOGICAL CHANGES OF DIABETIC NEPHROPATHY RATSObjective: Diabetic nephropathy rat models were established by injecting streptozocin intraperitoneally and feeded high fat diet longly and were treated by oral medication selenite longly.The study would investigate the influence of sodium selenite on basic conditions and pathological changes in kidney of diabetic nephropathy rats, so as to estimate the effect of sodium selenite preventing diabetic nephropathy.Methods: Diabetic nephropathy rat models were established by feeded high lipid diet and high consistency sucrose and injected intraperitoneally a single streptozocin (STZ) in a dose of 55 mg/kg for the rats. Three different groups of the rats were employed: control group, diabetic nephropathy group and selenite-treated group. Temperature were kept in a 20°C -28°C range. All rats were fed by separate cages, the food and water were ingested without limitation, natural illumination.All rats were not gave insulin and hypoglycemic agent in the whole process.After 10 weeks, the conditions of rats were observed. 24 hours'urine of the rats was collected by metabolic cage,which was used for detecting 24 hours'albumin and urine creatinine by kit. Rats were killed and serum was obtained from abdominal aorta, which was used to detect serum creatinine and serum glucose. Cut the kindey,cleaned the kindey amicula then douched the kindey by cool normal saline.The size,colour,texture and the weight of kindey were observed.The tablet renal cortex tissue was cut quickly and fixed with 4% glutaral to observe the fine structure by scanning electron microscope. Part of renal cortex tissue were fixed with 4% paraformaldehyde to make paraffin section which stained with HE to show kidney pathological changes by light microscope. All data were dealt with SPSS11.0 statistical software.Results: 1. The basic conditions of selenite-treated group were significant better than diabetic nephropathy group. Kindey/body weight and Serum glucose had no difference between selenite-treated group and diabetic nephropathy group, but there were great differences for Serum creatinine and 24 hours urinary albumin. 2. The pathological changes by light microscope and fine structure changes by electron microscope in kindey of selenite-treated group were better than diabetic nephropathy group.Conclusion: 1.Selenite can greatly improve the general body state of diabetic nephropathy rats.2.Selenite can delay the kindey pathological changes of diabetic nephropathy rats PART TWO THE INFLUENCE OF SELENITE ON p38MAPK,NEPHRIN,ADIPONECTIN EXPRESSION IN KIDNEY OF DIABETIC NEPHROPATHY RATSObjective: Diabetic nephropathy rat models were established by injecting streptozocin intraperitoneally and feeded high fat diet longly and were treated by oral medication selenite longly.The study would evaluate the effect of sodium selenite on expression of p38MAPK,nephrin,adiponectin, so as to study its molecule mechanism in DN.Methods:Diabetic nephropathy rat models were established by feeded high lipid diet and high consistency sucrose and injected intraperitoneally a single streptozocin (STZ) in a dose of 55 mg/kg for the rats. Three different groups of the rats were employed: control group, diabetic nephropathy group and selenite-treated group. Temperature were kept in a 20°C-28°C range. All rats were fed by separate cages, the food and water were ingested without limitation, natural illumination.All rats were not gave insulin and hypoglycemic agent in the whole process.After 10 weeks, the conditions of rats were observed. 24 hours'urine of the rats was collected by metabolic cage,which was used for detecting 24 hours'albumin and urine creatinine by kit. Rats were killed and serum was obtained from abdominal aorta, which was used to detect serum creatinine and serum glucose. Cut the kindey,cleaned the kindey amicula then douched the kindey by cool normal saline.The size,colour,texture and the weight of kindey were observed.The tablet renal cortex tissue was cut quickly and fixed with 4% glutaral to observe the fine structure by scanning electron microscope. Part of renal cortex tissue were fixed with 4% paraformaldehyde to make paraffin section for analyzing the protein expression of p38MAPK,nephrin and adiponectin by immunohistochemistry. Part of kindey was cut and freezed by liquid nitrogen to prepare total RNA and protein extracted by tissue bomogenate. RT-PCR and Western blotting were used to evaluate the mRNA and protein expression of p38MAPK,nephrin and adiponectin. The results were analyzed by Quantity One software.All data were dealt with SPSS11.0 statistical software.Results: 1. The expression of p38MAPK mRNA and protein in selenite-treated group decreased in compared with diabetic nephropathy group,but enhanced in compared with control group. 2.The expression of Nephrin mRNA and protein in selenite-treated group was more than diabetic nephropathy group,but less than control group. 3.The expression of adiponectin mRNA and protein in selenite-treated group markedly enhanced in compared with control group and was more than diabetic nephropathy group, the same as diabetic nephropathy group compared with control group .Conclusion: Selenite can increase the expression of adiponectin and nephrin, and decrease the expression of p38MAPK by suppressing oxidative stress and enhancing sensitivity to insulin, Which may be related to improve diabetic nephropathy of the rats.