CHRONIC PRENATAL AND POSTNATAL PB2-3] MK8O1 BINDING-SITES IN ADULT-RAT FOREBRAIN( EXPOSURE INCREASES [H)

We have measured the binding of [H-3]MK801 to the N-methyl-D-aspartate (NMDA) receptor-ion channel in membrane preparations from adult rat f orebrain exposed to lead (Pb2+) during gestation, lactation, and postw eaning. Our results indicate a 30.9% increase in the number of [H-3]MK 801 binding sites in Pb2+ exposed animals relative to controls. No sig nificant changes in the affinity constant were observed. The level of blood Pb2+ for which such changes were measured was 13.9 +/- 2.8 mu g/ dl. These results indicate that alterations in the NMDA receptor-ion c hannel complex are present at blood Pb2+ levels which are environmenta lly relevant and suggest that chronic Pb2+ exposure during development can influence the NMDA receptor complex in the adult rat brain.