DEPLETION OF RETINYL ESTERS IN THE LUNGS COINCIDES WITH LUNG PRENATALMORPHOLOGICAL MATURATION

Close to birth rat fetuses have lungs which are depleted in retinyl es ters. Glucocorticoids administered to pregnant rats accelerate this pr ocess. We have investigated changes in fetal lung levels of retinol an d retinyl palmitate and accompanying morphological changes after admin istration of dexamethasone to pregnant rats on day 18 of pregnancy. He re we show that this depletion temporarily coincides with prenatal mor phological maturation of the lungs. The data presented support the ide a that the maturational effect of glucocorticoids in the developing lu ngs is linked to vitamin A metabolism. (C) 1994 Academic Press, Inc.