1983 Volume 31 Issue 7 Pages 2459-2465
The metabolic fate of manganese after the oral administration of excessive manganese chloride in rats was studied. After a single oral administration of manganese chloride (100 mg Mn/kg), the manganese levels in most tissues temporarily increased and then rapidly decreased to the control values within 24-48 h ; however, the manganese levels in the pancreas, brain, and bone were considerably higher than the control values even at 48 h after the administration. The tissue levels of manganese in rats given a single oral administration of 200 or 400mg Mn/kg were markedly higher than those after 100mg/kg and remained much higher than the control and 100 mg Mn/kg values at 24 h after the administration. The increase in the tissue retention of manganese at such high doses was found to be due to a decrease in the biliary excretion of manganese, which is the major excretion route of the metal. On the other hand, when manganese (100mg Mn/kg) was given every other day for three months, little tissue accumulation of manganese was observed in rats.
