The development of lipid metabolism. Changes in the level of fatty acids in serum during postnatal ontogenesis in the rat.

ABSTRACT

In young rats of 5 different age groups the spectrum (per cent) of 6 FFA was determined. The results show, that palmitic acid (C160) represents the main FFA in all age groups; at the end of the first week forms nearly 50 per cent. In adult animals (8-week-old) values decreased to 26 per cent. Similarly, the myristic acid (C140) was found highest in suckling animals (10 per cent) and decreased with age. The ratio of saturated to unsaturated FA (S/U) decreased with age. In other animals of 7 different age groups the concentration of total and of individual FFA was investigated. The results were expressed in nmol.l-1. Results showed, that the total concentration of FFA during the first postnatal month is nearly 2-times higher than in adults. The ratio of S/U FFA decreased from 1.81 to 0.85. The concentrations of individual FFA showed different age-dependent trend. Myristic and stearic acids (C140 and 180) increased with age till the 4th week. The concentrations of palmitic, oleic and linoleic acids were high during the first 3 weeks of age and decreased after weaning. The concentration of palmitate-oleic acid (C161) was lowest in all age groups as well as that of palmitic (C 160) was always the highest. These results show, that changes in concentration of individual FFA with age are not dependent only on the intake of the milk. (Tab. 3, Fig. 1, Ref. 8).