Concentrations of lead in the soft tissues of male rats during a long-term dietary exposure

• Published in: Environmental research 1982-06, Vol.28 (1), p.147-153
• Main Authors: Mykkänen, H.M., Lancaster, M.C., Dickerson, J.W.T.
• Format: Article
• Language: English
• Subjects: Aging; Animals; Body Weight - drug effects; Brain - metabolism; Eating; Kidney - metabolism; Lead - administration & dosage; Lead - blood; Lead - metabolism; Liver - metabolism; Male; Rats; Rats, Inbred Strains
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/0013-9351(82)90163-3

Newborn rats of albino Wistar strain were exposed to lead from birth, first indirectly through maternal milk and then directly through a diet containing 0.5% lead acetate. At 3, 6, and 12 months of age some of the male rats were killed for the determination of the concentrations of lead in the blood, brain, kidneys, and liver. This long-term exposure resulted in a slight retardation of growth, yet no change in the food consumption was seen. Concentrations of lead in the blood and brain were similar at 3 and 6 months of age, but significantly higher at 12 months, while the concentrations of lead in the kidneys increased significantly with age. Of the brain parts examined the forebrain had the highest concentration of lead, which increased significantly with age. The present study, together with already published data, demonstrated clearly that lead accumulated in rat brain during the suckling period remains relatively unchanged throughout adult life, while the concentrations in the blood and other soft tissues fall rapidly after weaning. Thus the blood lead level cannot be used as a measure of the amount of lead in the brain, particularly in the case of long-term or intermittent exposure of the young.