Effect of maternal dexamethasone treatment on fetal lung vitamin A stores in the perinatal rat
Shenai, J.P.; Chytil, F.
International Journal for Vitamin and Nutrition Research. Internationale Zeitschrift für Vitamin- und Ernahrungsforschung. Journal International de Vitaminologie et de Nutrition 64(2): 93-97
1994
ISSN/ISBN: 0300-9831 PMID: 7960497 Document Number: 434275
Vitamin A (retinol) is essential for normal differentiation of developing respiratory epithelium. Significant vitamin A storage occurs in the fetal lung near term (gestational day 21) in the perinatal rat, and the developing lung may be dependent on these local vitamin A stores during growth and differentiation. The growth and differentiation of fetal lungs can be enhanced by maternal treatment with glucocorticosteroids. We conducted this study in rats to determine the effect of maternal dexamethasone treatment on the lung stores of vitamin A in the offspring. Vitamin A-sufficient pregnant rats were given by intraperitoneal injection a single dose of either dexamethasone (300 microgram) or 0.9% saline solution on gestational day 16. High performance liquid chromatography was used to measure concentrations of vitamin A and its esters, retinyl palmitate and stearate, in fetal and neonatal lungs and livers at times ranging from gestational day 19 through 21, and from postnatal day 1 through 7. The concentrations of vitamin A esters in the lungs of fetuses and newborn pups of the dexamethasone-treated animals were significantly lower than those of the control group in all determinations, the values ranging between 22 and 5O% of controls. In contrast, the concentrations of vitamin A esters in the livers did not differ significantly between study groups. We conclude that a prompt, sustained, and selective decrease in the fetal lung stores of vitamin A appears to occur following maternal antenatal dexamethasone treatment. This decrease in the fetal lung vitamin A stores might be due to increased utilization of vitamin A associated with enhanced differentiation of the fetal lung induced by maternal dexamethasone treatment. The possibility that glucocorticosteroid treatment in human mothers with imminent preterm deliveries might alter the lung vitamin A stores of their newborn infants at birth deserves attention.