The Acute Toxicity Study Of Sodium Selenite Revealed By Protemics In Brain Tissue Of Channel Catfish (Ictalurus Punctatus)

Selenium is an essential trace element for animals and human being. It serves as antioxidant, anti-stress, immunity enhancement, anti-tumor, etc. In this thesis, channel catfish as experimental research object, Conduct sodium selenite acute toxicity tests half lethal concentration intimidation brain pathological observation and brain differences proteomics research.In the first part, channel catfish was considered as the experimental research watched. Handling with sodium selenite, the channel catfish's behaviors were surveyed. The results showed that:the experimental samples were vulnerable to disturb, and lost their balance (showed swim in side directions, or backstroke, or rolling). The statistical analysis showed that the sodium selenite on the 96h half lethal concentration of 35.59mg/L.In the second part, based on the statistical analysis results of acute toxicity test, the live channel catfish cerebellum after half lethal concentration (35.59mg/L,96h) exposure test were taken and made into paraffin sections. The sections were observed with transmission electron microscopy (TEM). The results of paraffin sections showed that:the control group cerebellar cortex granular cells arranged regularly, granular layer structures were in integrity, showed in normal round shapes. The experimental group cerebellar cortex loose granular layer, edema, showing an empty net, granular cell collapse disappeared, some cells loss of normal round, triangular or irregular shape. TEM results show that:the control group within the cerebellar cortex is rich in organelles, mitochondria rich in cristae arranged in regular panels, structural integrity of myelin sheath. The experimental group cerebellar cortical cytoplasm edema, decreased cytoplasmic organelles, mitochondrial swelling, collapse of membrane structure, cristae dissolution disappeared, and some mitochondrial vacuolization, only to see the outline of mitochondria. Pathological observation shows that sodium selenite has certain toxic injury to the brain of channel catfish.In the third part, the survivals'brains which had been dealt with half lethal concentration 35.59mg/L exposed after 96h have been taken for the proteomics research. By optimizing 2-DE, a set of conditions for channel catfish brain dimensional electrophoresis system was obtained. Using ImageMaster software, the 2-DE maps of brain tissue from both the control group and the experimental group were analyzed, and the differences in protein spots were identified. The results showed that:1024±25 protein spots from the control group and 998±20 protein spots form the experimental group were isolated. The difference protein point was separate identification of biological mass spectrometry. And we get 9 proteins through to the NCBInr and EST databases retrieving. The three proteins peroxiredoxin-2, aldose reductase and carbonic anhydrase among it may be biomarkers of selenium strengthening the body antioxidant immune system proteins.