Ethanol and Fetal Nutrition Effect of Chronic Ethanol exposure on rat Placental Growth and Membrane Associated folic Acid Receptor Binding Activity

Abstract

Rat placental composition and specific folate receptor activity were measured at 20 days gestation in dams exposed to chronic high doses of ethanol (6%, vol/vol) throughout gestation and in isocalorically pair-fed controls. Ethanol-exposed fetuses were smaller (ethanol = 3.28 .+-. 0.08 vs. control = 4.01 .+-. 0.10 g, P < 0.001), but their placentae were larger (experimental = 0.534 .+-. 0.02 vs. control = 0.399 .+-. 0.01 g, P < 0.001). The increased wt appears to be secondary to hyperplasia as total DNA was increased while the wet/dry, RNA/DNA and protein/DNA ratios were not different. Despite larger placentae, specific folate receptor activity was significantly reduced in the ethanol-exposed tissue, whether expressed relative to membrane protein, placental wt or total placental binding. Ethanol exposure is evidently placentotoxic; an additional mechanism by which ethanol may lead to intrauterine growth retardation; decreased folate receptor activity is evident.