Abstract: ObjectiveTo observe effects of low level lead exposure during pregnanton expression of glial cell line-derived neurotrophic factor(GDNF)in hippocampus of offspring rats.MethodsThe rats were fed with doubly evaporated water in control group and 0.05%,0.2% lead acetate(PbAc)solution in treatment groups via drinking water during pregnancy and lactation.After weaning,the offspring rats were directly fed with drinking water as the irdams.Western blotting was used to detect the prote in expression of GDNF in hippo campus of offspring rats at postnatal 1,3,7,14,21,and 28 days, respectively.The contents of lead in blood and hippocamous were determined with a tomic absorption spectropho tometer at postnatal 28 days.The Morris Water Maze test was used to observe the change of learning and memory at postnatal 56 days.ResultsCompared to the control(9.01±1.60),the time of searching for the platform was significantly longer in offspring rats of 0.05% and 0.2% PbAc groups(16.43±2.89,24.85±4.44)in dose-effect manner(P<0.01).The expression of GDNF in hippocampus of 0.2% PbAc group at postnatal 1,3,7,and 28 days were 0.61±0.018,0.71±0.026, 0.70±0.030,and 0.62±0.033,which exhibited a decreased tendency(P<0.05,P<0.01)in dose-dependentmanne,rand different expression with time.ConclusionExposure to low level lead during pregnancy can decrease expression of GDNF in hippocampus of offspring rats and might be one of the molecular mechanisms of lead on learning and memory.