Elevation of blood lead concentration by confinement in the rhesus monkey

Rhesus monkeys were exposed to lead (Pb) acetate under various regimens during the first 12 months of life. At 30 months of age, these animals and unexposed controls were confined to an unfamiliar experimental chamber for one week. Serum cortisol concentration and Pb concentration in whole blood (PbB) were measured prior to, during, and after this confinement. Cortisol concentrations rose 60--90% within 2 hours of confinement, and declined to baseline levels after 98 hours of confinement. Mean baseline PbB levels reflected the state of clearance of the previously-ingested lead, rose 25--35% within 2 hours of confinement, and reached mean maximum levels as much as 100% above baseline after 98 hours of confinement. The data are discussed in terms of hormonal mobilization of Pb stored in bone, and subgest (1) that this storage is multicompartmental, (2) that more than one process is probably involved in its mobilization, (3) that cortisol probably does not directly affect PbB levels, and (4) that stress should be considered a potential factor in determining the PbB in studies of Pb metabolism.