EXPRESSION OF LIVER CARNITINE PALMITOYLTRANSFERASE-I AND PALMITOYLTRANSFERASE-II GENES DURING DEVELOPMENT IN THE RAT

The enzyme activity and the expression (protein and mRNA concentration s) of genes encoding for hepatic carnitine palmitoyltransferases (GPT) I and II were studied during neonatal development, in response to nut ritional state at weaning and during the fed-starved transition in adu lt rats. The activity, the protein concentration and the level of mRNA encoding CPT I are low in foetal-rat liver and increase 5-fold during the first day of extra-uterine life. The activity and gene expression of CPT I are high during the entire suckling period, in the liver of 30-day-old rats weaned at 20 days on to a high-fat diet and in the liv er of 48 h-starved adult rats. The activity and CPT I gene expression are markedly decreased in the liver of rats weaned on to a high-carboh ydrate diet. By contrast, the activity, the protein concentration and the level of mRNA encoding CPT II are already high in the liver of ter m foetuses and remain at this level throughout the suckling period, ir respective of the nutritional state of the animals either at weaning o r in the adult.