Serum lipoprotein profiles in mice: effects of early over- and undernutrition

Effects of early over- and undernutrition on lipoprotein profiles of adult Swiss male mice reared in litters of different sizes were investigated. Lipoproteins were isolated by density gradient ultracentrifugation and defined by chemical composition. Protein moieties were defined by their changes. The lipoprotein lipase (LPL) activity in epididymal adipose tissue, heart and diaphragm was measured. Early feeding patterns induced permanent body weight differences in adult mice. Serum phospholipid content was significantly higher in obese than in control mice. Overfeeding led to significantly higher activity of LPL in adipose tissue; inversely, undernutrition induced a lower LPL activity. There was a trend toward variations of lipoprotein concentrations in relation to litter size, with significant differences being observed only between obese and undernourished mice for LDL-HDL1 (low density lipoprotein--high density lipoprotein) and HDL2 concentrations. Compared with normally fed mice the most notable alterations in plasma lipoprotein composition were, in LDL-HDL1, greater cholesteryl ester in obese and less phospholipid in undernourished mice. In contrast, tetramethylurea-soluble apolipoprotein distribution was unaffected by litter size. Although moderate differences were observed in lipoprotein compositions and levels in over- or undernourished mice, further investigations of lipoprotein metabolism and metabolic abnormalities in this animal model are required.