[Changes in cholesterol and triacylglycerol serum levels in rats during postnatal ontogenesis]

In the serum of young normal rats during the first two months of life the concentrations of triacylglycerols (TG) and of cholesterol (CH) were determined. Low values in both studied parameters found in newborn animals were followed by a marked increase during the first week of life. In comparison with adult animals high values remained during the first five weeks of life. The results are discussed with regard to the high intake of lipids by milk during the period of sucking, as well as from the point of possible mobilization of tissue lipid stores because of the similar trend in the ontogenetic expression of the gene coding the hormone-sensitive lipase (HSL). On the basis of evaluation of the analytical as well as biological variance it was found, that for the level of 50% of confidentiality the serum concentrations of cholesterol should be in the range X +/- 0.26 mmol/l. For the level of 95% the range of values is X +/- 0.67 mmol/l. It is suggested that these results could be used as reference values for serum lipids in the rat during ontogenesis. (Fig. 1, Ref. 21.)