Chronic Lead Exposure Induced Learning and Memory Retardation in Young Rats

Objective To study the effects of chronic lead exposure on learning and memory ability in young rats and the mechanisms of lead-induced brain functions impairment.Mothods 20 post-wealing Wistar rats were divided into the tested group(n=7) and the control group(n=13).The experimental rats were red by 0 05% acetate lead solution and in the controls were only fed distilled water.Results The learning and memory ability were examined with Y-maze test,after the rats drinking the solution for 90～100 days,and then we measured their lead and Ca 2+ levels in blood and brain tissue.The Y-maze discrimination learning ability and memory keeping percentage in chronic lead exposure group were evidently lower than those of control group;(20 23±5.52) training times and (64.17±9 92%) vs (13 86±1 95) training times and (86 67±5 16)%,respectively(P0 01,t=2 95 and t=2 98);the blood lead(0 399±0 082μg/ml) and brain lead(2 189±0 818μg/g tissue) in rats of tested group were obviously higher than in the control group(0 049±0 012μg/ml,0 69±0 08μg/g tissue,respectively).Ca 2+ concentration in lead-exposured rats were lower than that in the control group,but the difference was no statistically significance(P0 05).Conclusions Chronic lead exposure can cause adverse effects on the learning and memory ability,the abnormal changes of Ca 2+ concentration may play an important role in the brain function disturbance associated with lead pollution.