Levels of Liver Retinol and Retinol Ester in Pregnant and Pseudopregnant Rats

Retinol and retinol ester concentrations were determined in the livers of pregnant rats throughout the 21-day period of gestation and compared with those observed in pseudopregnant controls. Data were analyzed by analysis of variance and the results showed that levels of retinol and its ester in the livers of pregnant animals were significantly higher than those for the pseudopregnant controls; differences were attributed to group × time interaction. The presence of decidual cells had no apparent effect on the concentration of liver retinol, but did appear to increase the concentrations of retinol ester in the liver. The relationship between liver retinol and its ester during pregnancy was discussed, and the evidence suggested that physiological changes in the fetal placenta or fetus were responsible for changes in the maternal levels of retinol and its ester.