Inhibition of progenitor cell proliferation in the dentate gyrus of rats following post-weaning lead exposure

Although lead is a potent developmental neurotoxin, the effects of postnatal lead exposure on progenitor cell proliferation in the hippocampus has not been examined. Postnatal day 25 rats were fed a lead containing diet (1500 ppm lead acetate) for 30-35 days and administered bromodeoxyuridine (BrdU, 50 mg/kg, i.p.) during the last 5 days of lead exposure. Animals were killed 24 h after the last BrdU injection. Proliferation of new cells in the subgranular zone and dentate gyrus was significantly decreased in lead-exposed rats compared to control animals that ate a similar diet devoid of lead. These results suggest that postnatal lead exposure can have significant deleterious effects on progenitor cell proliferation and thus the structure and function of the hippocampus. (C) 2004 Elsevier Inc. All rights reserved.