Glutamate and calcium uptake in astrocytes after acute lead exposure

The neurotoxicity of lead is well known, but the exact mechanisms of its toxicity are not solved yet. Disturbances in glutamate homeostasis of neural tissue and interactions of lead with calcium metabolism have been considered as a potential mechanism. In the present study, we evaluate the acute effect of lead exposure by studying glutamate uptake, as well as calcium influx and intracellular lead in cultured rat cerebellar astrocytes. Glutamate uptake and calcium influx were evaluated with radioactive probes by liquid scintillation counting, and intracellular lead was measured by atomic absorption method. Lead increased calcium influx dose dependently, but in an acute 15-min exposure it had no statistically significant effect on glutamate uptake into astrocytes. Calcium decreased at high concentrations but did not hamper lead uptake. Lead uptake rate into astrocytes was high compared to calcium.