The Effect Of Different Levels STI And Antioxidants On The Oxygen Free Radical Levels In Mice

Studies have shown that soybean trypsin inhibitors (STI) cause pancreatic hyperplasia and damage to pancreatic cells. This paper chosen Kunming male mice as test object to study the impact of different doses of STI on the animals pancreas, serum redox state and harm to pancreas structure and function and research the mechanism of pancreatic injury caused by STI from molecular level.1. Oxidative damage to the mice pancreatic caused by different doses of STIAfter feeding3weeks, the mice were sacrificed by decapitation and the serum and pancreas were taken to assay oxidation and antioxidation indicators, the activity of digestive enzymes and the level of hormone mRNA, made the pancreas tissue section and observed injury of pancreas structure by histological and transmission electron microscope. The results showed that:Compared with the control group, with the adding doses of STI, oxidation index (MDA) in serum and pancreas significantly increased, the activities of antioxidant enzyme, such as superoxide dismutase (SOD), dropped; activities of lipase etc. decreased while somatostatin (SS), insulin activities increased, total antioxidant capacity (T-AOC) ability descended. All the indicators had a dose-dependent manner with STI, indicating that pancreatic injury caused by STI related to free radicals generation.Histological analysis showed:the structures of acinar cells in0group is complete, with the adding doses of STI had a slight bleeding, a few white blood cells soaked and ill-defined margins, some nucleus were dissolved and disappeared.The results under transmission electron microscope were shown as follows:when the doses of STI is Othe ultrastructures of pancreatic acinar cells were normal.with the adding doses of STI,the shape of mitochondria were basically normal, the shape of some mitochondria changed apparently, accompanied with slight swelling, irregularly nucleus shape,the mitochondrial cristae disappeared, degree of the vacuolation increased and there was irregularly nucleus shape and vesiculation of endoplasmic reticulum dilatation. Zymogen granules could not be seen.The results of quantitative real-time PCR demonstrated the up-regulated expression of CAT、 GSH-PX、SOD\SST、SSTR-5、Try gens was with the increase of STI dosage. All the above indicating that gens expression of relative indicators were changed due to different doses of STI.In the synthesis, with the increase of STI doses in the diets, the level of free radicals increased, oxidative stress station was enhanced, the severity of pancreas injury caused by STI has a relationship with STI doses.2、Under different levels of antioxidants (Vc) intervention, the effect of STI on oxidative damage of pancreatic structure After feeding3weeks, the mice were sacrificed by decapitation and the serum and pancreas were taken to assay oxidation and antioxidation indicators, the activity of digestive enzymes and the level of hormone mRNA, made the pancreas tissue section and observed injury of pancreas structure by histological and transmission electron microscope. The results manifested that:Compared with the control group, with the adding doses of Vc, oxidation index (MDA) in serum and pancreas notably decreased, such as superoxide dismutase (SOD), rised; activities of lipase etc. decreased while somatostatin (SS), insulin activities decreased, Histological analysis indicated:structures of acinar cells in group1were complete, disorganized structures and ill-defined margins appeared in group2, some nucleus were dissolved and disappeared. There was karyopyknosis and irregularly nucleus shape in group3, and a few white blood cells soaked. Group4and5had ill-defined margins.The results under transmission electron microscope were shown as follows:the ultrastructures of pancreatic acinar cells were normal. The shape of mitochondria in group2was irregularly, swelling degree increased, endoplasmic reticulum dilatation vesiculated and zymogen granules disappeared, with the adding doses of Vc A few mitochondria swelled and had rich endoplasmic reticulum, a small mount of zymogen granules could be observed, the shape of mitochondria was regularly, the cristae could be seen, endoplasmic reticulum was rich and a few had dilatation.The results showed that the increasing of antioxidants can decrease the level of free radicals and alleviate pancreas injury.The results of quantitative real-time PCR demonstrated the down-regulated expression of CAT、GSH-PX、SOD gens was with the increase of antioxidants dosage. SST、SSTR-5、Try genes were down-regulated.To sun up, under the intervention of antioxidants, the production free radicals decreased, the state of oxidative stress was improved and the pancreas injury was relieved.