Glutamate and calcium uptake in astrocytes after acute lead exposure

The neurotoxicity of lead is well known, but the exact mechanisms of its to xicity are not solved yet. Disturbances in glutamate homeostasis of neural tissue and interactions of lead with calcium metabolism have been considere d as a potential mechanism. In the present study, we evaluate the acute eff ect of lead exposure by studying glutamate uptake, as well as calcium influ x and intracellular lead in cultured rat cerebellar astrocytes. Glutamate u ptake and calcium influx were evaluated with radioactive probes by liquid s cintillation counting, and intracellular lead was measured by atomic absorp tion method. Lead increased calcium influx dose dependently, but in an acut e 15-min exposure it had no statistically significant effect on glutamate u ptake into astrocytes. Calcium decreased at high concentrations but did not hamper lead uptake. Lead uptake rate into astrocytes was high compared to calcium. (C) 2001 Elsevier Science Ltd. All rights reserved.