Effect of litter size on plasma cholesterol and insulin and some liver and adipose tissue enzymes in adult rodents.

Rats and mice were raised in litters of 4 or 14 per mother. Plasma levels of cholesterol and insulin were found to be elevated later in life in those raised in small litters. Hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity in rats was higher in large than in small litters on day 60 but not on day 240. In adipose tissue activity was higher in the small litters. The activities of phosphoenolpyruvate carboxy-kinase in liver and of fatty acid synthetase in adipose tissue were higher in large than in small litters later in life. It is concluded that early quantitative changes in food intake have permanent late effects.