Chronic ingestion of Mn3O4 by young rats: tissue accumulation, distribution, and depletion.

Mn accumulation, distribution, and disappearance were evaluated in selected tissues of preweanling rats dosed daily with particulate Mn3O4 for 12 or 27 d postpartum. Significant findings include a high rate of Mn absorption and localization in tissues, especially the cerebrum, hypothalamus, and pituitary. In these tissues, the return of Mn concentrations to control levels was much slower when Mn dosing was continued beyond 18-20 d postpartum.