248 Maternal Nutrient Restriction During Mid-gestation Decreases Uteroplacental Release and Fetal Uptake of Essential Amino Acids in Sheep

Abstract To examine the effects of maternal nutrient restriction on net uteroplacental flux during mid-gestation, 14 singleton ewes (48.2 ± 4.0 kg body weight) were fed 100% (control; CON; n = 7) or 60% requirements (restricted; RES; from day 50–90 (mid-gestation). On 90, blood flow was measured via Doppler ultrasonography and samples collected femoral artery, uterine vein, umbilical vein. Blood vessel glucose amino acids (AA) concentrations arterial-venous (uterine, AV; fetal, va) differences fluxes calculated. Data analyzed using GLM procedure SAS for treatment. Nutrient mid-gestation did not influence (P ≥ 0.17) flows. Uterine AV fetal va total, essential, nonessential AA influenced > 0.10) by restriction. decreased ≤ 0.05) release total tended to decrease 0.07) uptake fetus. Uteroplacental essential 0.03) with RES 53.4% 45%, respectively. but, affected 0.14). 0.04) methionine, phenylalanine, threonine, valine isoleucine, leucine, tryptophan. Umbilical artery 32% lesser 0.01) increase 0.08) uptake. altered in current study. The results may indicate that metabolism shifts adapt reduced supply which greater utilization.