Effets of endotoxin on apoptosis of pancreatic islet cells in rats / 中国糖尿病杂志

ABSTRACT

Objective　To explore the mechanism of effects o f endotoxin (LPS) on apoptosis of pancreatic islet cells in rat.Metho ds　After the model of endotoxemia was established in rat with intrap eritoneal injection of LPS (2mg/kg),the changes of nitric oxide (NO) level in se rum and pancreas were dynamically determined.The expression of inducible nitric oxide synthase (iNOS) was also observed by situ hybridization in the islet,Moreo ver,DNA damage in islet cells by the external donor of NO (sodium nitroprussid e) and LPS in vitro with single cell gel electrophoresis and agarose gel electro phresis of DNA were also evaluated.Results　NO level in se rum was significantly increased at the 6th,and persisted to the 3rd day after in jection of LPS,the NO in pancreas was also elevated,but recovered to the normal at 24h. The expression of iNOS in pancreatic islet also began to enhance at the 6th and significantly enhanced at the 12th after endotoxemia.In vitro experiment sho wed that exogenous NO markedly caused the damage of DNA in islet cells,but LPS d i d not exert the same effects.Conclusion　The mechanism of the effcts of endotoxin on apoptosis of islet cells might stimulate the expressi on of iNOS in inflammatory or non-inflammatory cells that generates the NO indu cing the DNA damage of islet cells.