Expression of fatty acid binding protein in the liver during pregnancy and lactation in the rat.

Expression of the liver fatty acid binding protein (L-FABP) has been studied in the liver of pregnant and lactating rats. The L-FABP concentration found in the cytosol by immuno-enzymatic assay (ELISA) was consistently higher in the dams during the pregnancy and the lactation than in the age-matched virgin females. Paradoxically, a decrease in the L-FABP mRNA level occurred in the maternal liver during the last days of the gestation. This level remained low on days 7 and 14 of the lactation. Since the transcription rate of the L-FABP gene was unchanged in the maternal liver, these data suggest a post-transcriptional regulation of the L-FABP during pregnancy and lactation in the rat. The nutritional adaptations occurring during pregnancy and lactation are not involved in this regulation since a chronic maternal food-restriction failed to correct these modifications. The mechanism of this regulation is presently unknown, but possibilities include hormonally mediated effects.