Expression Of CSD In Rat Islet Cells, And Prevention Study Of Taurine In Diabetes

Taurine is a kind ofβ-sulfur amino acid.In recent years,studies have shown that taurine can maintain osmotic pressure,regulate calcium balance,anti-oxidation and et al.As a nutrient,taurine is essential for human health.Cysteine sulfinate decarboxylase(CSD) is the major rate-limiting enzyme,whose activity reflects the ability of taurine biosynthesis.According to the NCBI gene sequence of CSD in rat brain,designed a pair of specific primers.After separation and purification of rat islet cells,total RNA were extracted for RT-PCR amplification.After being reclaimed,the amplified products were connected with the PMD18-T cloning vector and transformed into DH5αcompetent cell of E.coli.After the identification of bacteria,the gene was sequenced and analyzed.Sequence analysis results showed that the amplified product was the CSD gene in islet cell.Its homology with rat brain CSD reaches 99%,while with mouse embryonic CSD reaches 91%.The results proved the existence of CSD gene in rat islet cells,and rat islet cells can biosynthesize taurine.As a broad-spectrum antibiotic,streptozotocin(STZ) can selectivily destruct pancreaticβceils,and establish type I diabetes model.Through adding STZ to the medium to deal with the islet cells in vitro.By semi-quantitative RT-PCR method,relative expressions of CSD gene in diabetes and control groups were determined.The results showed that the levels of control groups were significantly higher than that in diabetes groups.Therefore,we speculated that taurine involved the occurrence and development of diabetes,some diabetic symptoms may be due to the lack of taurine.The male Wistar rats were randomly divided into five groups,normal control group, diabetes mellitus model group(DM group),low-dose taurine group(0.6g/kg bwTau),medium -dose taurine group(1.2g/kg bw Tau),high-dose taurine group(2.4g/kg bw Tau). Administration of different concentrations taurine to prevention groups,the normal control group and the DM model group administered thickener daily.After 4 weeks,DM model groups and taurine prevention groups rats were intraperitoneal injected streptozotocin as 50mg/kg body weight to establish diabetes mellitus model,and normal control group rats were intraperitoneal injected buffer solution.Each groups continued to oral administrating for one week,and blood glucose,weight,and a variety of blood biochemical were detected. Diabetes group rats have been maintained at a high level of blood glucose,and taurine groups were reduced to varying degrees in 3 days and 7 days,in which the effect of high dose groups significantly;For weight,the body weight in diabetic rats significantly decreased after establishment model,and taurine can prevent the occurrence of such circumstances; Administration high,medium and low doses of taurine increased insulin levels,but the results were not significant;But at the same time significantly reduced the levels of glucagon in serum;In addition,taurine reduced serum TG,TC,MDA,increased SOD,T-AOC,HDL in different levels.The experiments proved that the taurine can ameliorate the symptoms of diabetic rats to some extent,inhibit the decreasing of weight,decrease blood glucose of diabetic rats,enhance the antioxidant capacity,and improve the lipid metabolism.In conclusion,taurine biosynthesized in islet cells may be involved in the regulation of pancreatic endocrine.The hypoglycemic mechanism of taurine added exogenous include reduced glucagon,enhance antioxidant capacity and improve the lipid metabolism...