The Nutritional Intervention Mechanisms Of Calcium On Lead Brain Rats

[Objective] To investigate the influence of different doses of calcium on lead organization bivalent mineral elements in rats and the hippocampus or cortex organization form, from the molecular level research lead calcium to dye the influence of the hippocampus and cortex of rats, thus to explore the mechanism of calcium on lead induced injury to the nervous system, and provide theoretical basis for further calcium supplements to prevent lead absorption.[Methods] In the test,60 healthy (50±2) g male rats were randomly divided into five groups, and named as normal control group (normal diet, distilled water), lead exposed group (normal diet, 0.2% lead acetate water), Test Ⅰ group (0.5% calcium carbonate + normal diet, 0.2% lead acetate water), Test Ⅱ group (1% calcium carbonate + normal diet,0.2% lead acetate water) and Test Ⅲ group (2% calcium carbonate + normal diet,0.2% lead acetate water), respectively. After 60 days of continuous feeding, the hippocampus and cortex were collected or calculated calcium, iron, lead, zinc, copper, manganese, magnesium content. The hippocampus and cortex histopathological changes were observed by HE stain. The expression of levels of Grm5, Camk2a, Grinl, Homerl, Prkca and ERK2 were studied by real-time RT-PCR. In addition, and protein expression in rat hippocampus CaMK Ⅱ was determined by Western-blotting.[Results] (1) Compared with the control group, brain index were significantly decreased in each group; compared with the lead exposed group, with the calcium content increased, brain index increased, and the differences were highly significant (P< 0.01), and the test group Ⅱ brain index is maximized.(2) Compared with the control group, we observed that the content of calcium, zinc, iron, magnesium were significantly decreased on lead group (P<0.01), lead levels significantly elevated (P<0.01), copper, manganese content did not significantly changes. Compared with the lead exposed group, the test groups content of calcium, iron, magnesium were significantly increased in the brain tissue (P<0.01), and the test group in were the highest; zinc content were extremely significant (P<0.01), and the test group Ⅱ were the highest; the lead content was reduced significantly, the differences of test group Ⅱ, Ⅲ were extremely significant (P<0.01), and the test group Ⅱ was the lowest; copper, manganese content did not obviously change.(3) Compared with the control group, we observed that the lead group hippocampus and cortex of the small number of cells, the cell layer thinner, smaller size, cell gap increases, the shape is relatively simple, the nucleolus is not clear. Compared with the lead group, the number of test Ⅱ group hippocampus and cortex cells increased, the volume increases, the cell gap narrowed more clear nucleolus, most cell structure intact; test Ⅲ group hippocampal nuclei relatively clear, but the small number of cells, cell gap large; small body cortical cells, nucleoli are not clear.(4) Compared with the control group, the mRNA expression levels of the hippocampus and cortex of lead exposed group in Grm5, Camk2a, Grinl, Homerl, Prkca, ERK2 mRNA were significantly reduced (P<0.01). Compared with the lead exposed group, test group I Grm5, Camk2a, Prkca, ERK2 mRNA in hippocampus and expression levels Homerl, Camk2a, Grinl mRNA in cortex was significantly increased (P<0.05, P<0.01); test group Ⅱ and Ⅲ of target gene mRNA expression levels were significantly higher in hippocampus and cortex (P<0.05, P<0.01).(5) Compared with the control group, the protein expression of CaMKII was decreased significantly in the lead exposed hippocampus(P<0.07). Compared with the lead exposed group, the protein expression of test group Ⅱ were extremely increased (P<0.01), and the test group Ⅱ protein expression was the highest.[Conclusion] In conclusion, The appropriate dose of calcium supplement can make the two price of mineral elements in rats brain tissue elements are relatively stable, can alleviate the effects on hippocampal and cortical injury in rats, and the expression of content to lead intervention mechanism of quantity of CaMKII protein expression in the hippocampus, and intervent Grm5, Camk2a, Grinl, Homerl, Prkca and ERK2 mRNA content in hippocampus and cortex.