ABSTRACT
Objective The effect of lead exposure on children is consistently associated with intellectual and other neurologic deficits.However the exact mechanism by which Pb~(2+) exerts toxic effects on developmental central nervous system remains unknown.Our group has found by gene-chip test that the expression of metabotropic glutamate receptor subtype 5 (mGluR5) mRNA was changed by lead exposure.The present study aimed to examine the effects of different level of lead exposure on the expression of mCluR5 in gestation and lactation.Methods Sprague-Dawley rats were exposed to lead acetate during gestation and lactation.Three concentrations of 0.05%,0.2%,and 0.5% lead acetate were applied and considered as low,middle and high exposure group respectively.The Pb levels of blood and hippocampus of pups were analyzed at weaning to evaluate the actual lead content at the end of the exposure.The impact of lead exposure on the expression of mGluR5 mRNA and protein in hippocampal tissue of pups was investigated by quantitative real-time polymerase chain reaction (PCR) and Western blot.The potential role of the expression of mGluR5 mRNA and protein in lead neurotoxicity were discussed.Results The levels of lead in blood and hippocampus from lead-exposed rats were significantly higher than those in the controls and positively related to the degree of lead exposure.The results of real-time PCR and Western blot showed that exposure to lead acetate decreased the expression of mCluR5 mRNA and protein with a dose-dependent manner.Conclusions Hippocampal mGluR5 might be involved in lead-induced neurotoxicity.