Chronic manganese oxide administration to preweanling rats: manganese accumulation and distribution.

Mn accumulation was evaluated in selected tissues of preweanling rats dosed daily with particulate Mn3O4. Significant findings include a high rate of Mn accumulation in the preweanling rat; a Mn dose-related acceleration of postpartum liver iron depletion; a Mn dose-related depression in red blood cells, hematocrit, hemoglobin, body weight, and survival by 21 d postpartum; and a Mn distribution in tissues with liver greater than brain greater than or equal to kidney greater than testes at 18-21 d of age.