Placental Transport of Nutrients and Fetal Metabolism in Intrauterine Growth Restricted Rats

Abstract

Previous studies show that reduced uterine perfusion results in intrauterine growth restriction and impaired fetal nutrition. However, the mechanisms involved are not totally understood. The objective of this study was to investigate whether reduced uterine perfusion alters placental transport of glucose and fatty acids in growth‐restricted fetuses. We used a rat model of growth‐restricted offspring induced by reduced uterine perfusion at 14 days of gestation. At 19 days of gestation fetuses and placentas were excised by cesarean section followed by collection of fetal and maternal blood and tissue. GraphPad software was used for statistical analysis with significance set at P<0.05. Reduced uterine perfusion resulted in male and female growth‐restricted fetuses with lower body weight and placental size compared to controls (P<0.05); and greater placental efficiency in female fetuses. Protein concentration and gene expression of placental glucose transporters GLUT2 and GLUT3 and fatty acids transporter FATP1 were elevated in growth‐restricted fetuses compared to controls (P<0.05). Glucose levels were elevated in female growth‐restricted fetuses compared to male and controls (P<0.05). Analysis of correlation between placental efficiency and fetal glucose level showed negative correlation (Pearson r=‐0.7939) in controls and positive correlation (Pearson r= 0.0747) in growth‐restricted fetuses. These results suggest that reduced uterine perfusion induces compensatory changes in glucose and fatty acids placental transporters to ensure fetal survival and also results in changes on glucose homeostasis in growth‐restricted fetuses