Inhibition of the specific 3H-DL-Glu binding in the hippocampus of rat brain by lead.

The effect of Pb2+ on 3H-DL-Glutamate (3H-DL-Glu) binding in the membrane preparations from the hippocampus of rat brain was investigated with a view to explaining the cognitive and learning deficits produced by the heavy metal. The results indicated that Pb2+ (3.1-25.0 mumol.L-1) inhibited 3H-DL-Glu binding in a concentration-dependent manner. Scatchard analysis further revealed that at a concentration of 6.3 mumol.L-1 Pb2+ interfered with binding mainly through significantly decreasing the density of binding sites. This finding provided an important insight into Pb2(+)-induced impairments in learning and memory previously documented in children and in experimental animals chronically exposed to Pb2+.