Altered high density lipoprotein composition in manganese-deficient Sprague-Dawley and Wistar rats

The objective of this experiment was to determine whether changes in liver cholesterol content, plasma lipids and lipoprotein composition result from dietary manganese (Mn) deficiency in the Sprague-Dawley (SD) and the Wistar (W) rat. Weanling rats of both strains were fed Mn-deficient (1 ppm Mn) or Mn-adequate (45 ppm Mn) diets for 10 wk. After the 10-wk period rats were killed and plasma, liver, kidney and heart were collected. Liver, kidney and heart Mn concentrations were significantly lower in the rats fed the Mn-deficient diet than in controls. Plasma high density lipoprotein (HDL) (density 1.050-1.1963) was isolated by sequential ultracentrifugation. Plasma cholesterol levels were similar for all groups. HDL protein, cholesterol and apo E levels were significantly reduced with Mn deficiency. A shift to a smaller HDL particle was associated with Mn deficiency, based on gradient gel electrophoresis. The shift in size was more pronounced in the SD strain. Liver concentrations of total and free cholesterol were lower with Mn deficiency but more noticeably in the SD group. The results of our study suggest a role for Mn in HDL metabolism in vivo in both SD and W rats with a trend toward a greater effect in the SD strain.