Mid-gestation transcriptional control of eNOS in the placenta and uterine-umbilical vasculature in an ovine model of fetal growh restriction

Abstract

UTERINE-UMBILICAL VASCULATURE IN AN OVINE MODEL OF FETAL GROWH RESTRICTION BRADLEY T. ZIEBELL, JUAN A. ARROYO, RUSSELL V. ANTHONY, THOMAS A. PARKER, TIMOTHY R. H. REGNAULT, HENRY L. GALAN, University of Colorado Health Sciences Center, Obstetrics and Gynecology, Denver, Colorado, University of Colorado Health Sciences Center, Pediatrics, Aurora, Colorado OBJECTIVE: Decreased eNOS protein content in placental & vascular tissues at 95 days gestation age (dGA) may lead to reduced uterine-umbilical blood flows, increased placental flow resistance and systemic hypertension near term in a hyperthermic (HT) ovine model of fetal growth restriction (FGR). Our hypothesis is that eNOS mRNA expression is decreased at mid-gestation in this model of FGR. STUDY DESIGN: 4 ewes were exposed to HT conditions for 55 days beginning at 35dGA to induce FGR and 4 were used as controls. Placentomes were separated into caruncles and cotyledons, and umbilical/uterine vessels were collected at necropsy at 95dGA. Total RNA was extracted and cDNA was produced by reverse transcription. Real-time PCR analysis was used with published ovine eNOS primers (Acc #DQ015701) to determine eNOS mRNA expression. RESULTS: HT placentae were significantly smaller (440G60g vs. 186G18g; p%0.004) with no difference in fetal size. eNOS mRNA expression in HT pregnancies was decreased in the caruncles (3-fold; p=0.052), cotyledons (2-fold; p%0.04), umbilical vein (2-fold; p%0.01), and non-significantly in the umbilical (2-fold) and uterine artery (5-fold).