Investigation Of Heavy Metal Residues Of Crab In South Area Of Jiangsu Province And Preliminary Study On Effect Of Cadmium On Osteoblast

The research has developed a method for detecting heavy metals,such as Pb, Cd, Cu,Cr,As,Hg elements,in tissues of Eriocheir siensises, the fodder,water and soil in breeding environment by Atomic Absorption Spectrometry (AAS) , Atomic Fluorescence Spectrometry(AFS). The research facilitated us to discriminate the animal food polluted and know the corelation between environmental pollution and deleterious residues in animal food. Thus,it assisted us to develop the security of breeding Eriocheir siensises in this area,if it works,we can establish a base breeding Eriocheir siensises for export,make sure the security,sanitation,quality by standard breeding to promote the industry of breeding Eriocheir siensises,raise awareness of hazards of environmental pollution,build the base of green food and safeguard our environment.The results showed that heavy metals,such as Cr,Cu,As,Pb and Hg,in gonad tissues were relatively lower than those muscle tissues from brisket and crura of Eriocheir siensises in South Area of Jiangsu Province,then the content of Cd is opposite. in which the mainly polluted elements were Cu,As and Pb. In some specific tissues, both exceeded the maximum residue limits. but the exceeding is not obvious.The heavy metals of the fodder,water and soil in breeding environment did not exceed the maximum residue limits.At the same time,The osteoblastic cells were harvested by sequential enzyme digestion from calvaria of Sprague Dawley rats and then cultured. They were treated with Cd2+, then the proliferation was analyzed by MTT methods; PNPP method was used to assay the ALP activity of osteoblastic cell;the levels of osteocalcin in both secreted (in medium) and cellular ofosteoblasts were determined by radiate immunochemistry method;to analyze the mineralization ability of osteoblastic cells,the number and area of mineralization nodes were observed; cell apoptosis was observed by fluorescence microscopy-acridine orange/ethidium bromide double staining.Cd2+(0.75 to 4.0μmol/L) significantly inhibited the proliferation of osteoblastic cells ( P <0.01);Cd2+ inhibited the ALP activity at 24h,48h and 72h;particularly at 72h(P<0.01);The levels of osteocalcin in osteoblasts had no changes among groups, but the level in cultore of administrated groups reduced significantly contrast to the contro;Cd2+ significantly inhibited osteoblast mineralization at the concent ration of 0.5μmol/L and 1.0μmol/L;apoptosis was observed in the osteoblastic cells exposed to 1.0μmol/ L and 2.0μmol/L Cd2+.Cd2+significantly inhibits boneformation of osteoblastic cells by inhibiting the proliferation,differentiation and mineralization of osteoblastic cells and promoting osteoblastic apoptosis.