[Activation of glutamate uptake in rat hippocampal synaptosome by lead]

In order to investigate the mechanism of effects of lead on learning and memory, an experiment of glutamate uptake in the hippocampal synaptosome of rats was carried out. Results showed that (1) uptake of 3H-DL-glutamate increased by 70.38% to 193.24% in the synaptosome by exposure to 3.1 to 50.0 mumol/L of lead for 15 minutes in vitro, with a dose-dependent relationship; and (2) uptake of 3H-DL-glutamate increased by 65.73% to 124.93% after exposuring to 10 to 1,600 micrograms/ml of lead in drinking water for 30 days, also in a dose-dependent manner with lead content in the hippocampus. It suggests that lead ion can accelerate the clearance of glutamate transmitter and cause inhibitive effects.