Influence of dietary fat and cholesterol on milk lipids and on cholesterol metabolism in the rat.

The experimental basis for a hypothesis of Reiser and Sidelman (J. Nutr. 102: 1009, 1972) that cholesterol intake early in life is inversely related to an animal's subsequent hypercholesterolemic response to dietary cholesterol was tested. Female rats (seven per group) were fed either a stock diet (group 1), a semisynthetic diet with 15% lard (group 2) or the semisynthetic diet with 15% lard and 1.5% cholesterol (group 3) from day 18 of gestation and during lactation. Plasma cholesterol concentration during lactation was significantly higher in group 3 dams, but there were no significant effects of maternal diet on milk cholesterol or triglyceride concentration. Pups had access to the dams' diet until weaning at 30 days of age. Plasma and liver cholesterol concentrations at weaning were significantly higher in pups from group 3 dams than in those from the other groups. All pups were fed a semisynthetic diet containing 10% lard and 0.5% cholesterol from 60 to 161 days of age. Plasma cholesterol concentration during this time was significantly lower in male pups from group 1 dams than in those from other dams. Plasma cholesterol concentration in female pups showed a similar trend and was, on the average, significantly higher in females than males. Pup liver cholesterol concentration after weaning was not significantly influenced by maternal diet. Thus, these data do not support the hypothesis that cholesterol intake in early life is inversely correlated with subsequent response to dietary induced hypercholesterolemia.