Lead accumulations in brain, blood, and liver after low dosing of neonatal rats.

Newborn rat pups were treated in seven groups: Group 1, the control, was untreated and killed at birth (day 1); Groups 2, 3, and 4 were treated on postnatal days 1 through 10 with respectively saline or lead acetate, 5.0 mg/kg and 7.5 mg/kg body weight; Groups 5, 6, and 7 were treated with the same respective dosages on days 11 through 20. Cerebellum, cerebral cortex, brainstem plus hippocampus, liver, and blood were analyzed for lead. Neonatal rats killed at birth all contained some lead, the cerebellum having the highest concentration. Tissue from most treated groups accumulated lead in a dose-dependent manner. A comparison of lead concentrations between the organs of rats dosed days 1-10 and rats dosed days 11-20 indicated that the latter accumulated less lead per gram of tissue (p less than 0.05) than their younger litter mates.