EFFECT OF PRENATAL DEXAMETHASONE ADMINISTRATION - FETAL RABBIT INTESTINAL NUTRIENT-UPTAKE AND DISACCHARIDASE DEVELOPMENT

To examine the effect of prenatal steroids on fetal intestinal maturat ion, eight pregnant rabbits received either dexamethasone (Dex) or sal ine (Cont) on Days 25-27 of a 31-day gestation. As the rabbit provides a model of growth retardation based on uterine position, fetuses were identified as favored (Fav) or runt (Runt), generating four study gro ups: ContFav, ContRunt, DexFav, and DexRunt. On Day 31 the small intes tinal uptake of glucose and proline was measured by an everted sleeve technique. Additionally, lactase and maltase activity was determined. Small intestinal length and nutrient uptake was significantly increase d in the Dex fetuses. Control runts had a trend to decreased levels of nutrient uptake when compared to their favored counterparts. This tre nd reversed in the Dex fetuses with runt nutrient uptake surpassing th at of the favored fetus. A trend to increased enzyme activity of both lactase and maltase was demonstrated. This report provides the first d escription of maternal steroid administration causing a marked increas e in fetal small intestinal length and glucose and proline absorption in an in vivo model of intrauterine growth retardation. (C) 1993 Acade mic Press,Inc.