Metabolic effects of dietary manganese supplementation in ob/ob mice.

When fed a manganese-sufficient (20 ppm) diet, obese (ob/ob) mice have reduced levels of Mn in liver and brown adipose tissue (BAT), and depressed activities of succinate dehydrogenase (SDH) and manganese-containing superoxide dismutase (MnSOD) in BAT, compared to lean mice. Dietary Mn supplementation (200 ppm Mn) increased the Mn concentration in BAT in lean and obese mice and the Mn content of liver in the ob/ob mouse. Mn supplementation also led to an increase in the specific activities of SDH and MnSOD in BAT of lean and obese mice. In the obese mouse, these changes were paralleled by changes in the histological appearance of the tissue. The results indicate that the metabolism of Mn is altered in the liver and BAT of ob/ob mice, and that these alterations are responsive to dietary Mn supplementation.