Effects of perinatal exposure to methylmercury on changes of hippocampal ultrastructure and expression of metabotropic glutamate receptor 2,3,5mRNAs in offspring's mice
ZHANG Hong,YAN Chong-huai,WU Sheng-hu,XU Jian,TANG Fei-ge,ZOU Xiang-yu(Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai Institute for Pediatric Research,Shanghai Key Laboratory of Children's Environmental Health,Shanghai 200092,China)
Objectives To observe the effects of perinatal exposure to methylmercury on the changes of hippocampal ultrastructure and the expression of metabotropic glutamate receptor(mGluR)2,3,5 mRNAs in offspring's mice. Methods Pregnant mice were randomly divided into four groups consisting of control group and low-dose,moderate-dose and high-dose groups. The mice in four groups were respectively fed with methylmercury chloride at the doses of 0,1,2 and 4 mg/kg·d from the gestation day 1 to the postnatal day 18. The offspring's mice were respectively killed on 18,21,42 and 60 d after birth for the observation of the hippocampal ultrastructure with electron microscope and the detection of mGluR2,3,5 mRNAs expression with fluoresce quantified PCR,respectively. Results The hippocampal injury was aggravated or ameliorated significantly with the increase of exposure to methylmercury dose or with the increase of unexposure time,respectively. The expression of mGluR3 and mGluR5 mRNAs in the control group,low-dose group and moderate-dose group decreased with the increase of exposure to methylmercury dose,while there was a higher expression of mGluR3 and mGluR5 mRNAs in high-dose group comparing to those in moderate-dose group . The expression of mGluR2 in low-dose group was lowest among all four groups,and intensified in moderate-dose and high-dose groups with the increase of exposure to methylmercury dose. The all expressions of mGluR2,3,5 mRNAs in the low-,moderate-and high-dose groups were lower than those in the control group on postnatal day 21,42 and 60,although the expressions in three groups tended to intensify with the increase of the day age. Conclusions The hippocampal injury may be aggravated with the increase of perinatal exposure to methylmercury dose. The expression of mGluR2,3,5 mRNAs may be changed with the increase of exposure to methylmercury dose,however,there is no significant dose-effect relationship to be confirmed between them.
【Fund】： 上海市环境与儿童健康重点实验室、上海市重点学科、上海市医学重点学科资助项目(No.T0204);; 上海市教委基金资助项目(No.04BB16)
【CateGory Index】： X174
【CateGory Index】： X174