Effects of labor on placental fatty acid β oxidation

Objective: To measure the effect labor exerts on fatty acid (FA) oxidation in term human placentas, and to compare enzymes expression and activity between placenta and liver. Methods: Placental samples were collected: (a) scheduled non-labored cesarean section and (b) normal vaginal delivery at or beyond 37 weeks. Long and medium-chain FA oxidation were measured using 3H-labeled FA, ATP concentration was measured via commercial kit. Activity and expression levels of 11 FA enzymes were measured and results compared to both human and mouse liver. Results: Placentas undergoing labor had significantly decreased palmitate oxidation and ATP levels. Octanoic acid oxidation was 10-fold higher than palmitic acid oxidation. No difference in expression or activity level was detected between the groups. Conclusion: Term human placentas express all the enzymes required to oxidize FA, at a rate 20-fold lower than liver. FA Oxidation is not likely an important placental energy source during labor. Further work is needed to determine the functionality of this pathway in placenta.