Energy metabolism in umbilical endothelial cells from preterm and term neonates.

AIM The aim of this study was to investigate the impact of gestational age on energy metabolism in human umbilical vein endothelial cells (HUVECs) of preterm and term neonates. METHODS Activities of respiratory chain (RC) complexes I-V, citrate synthase (CS), overall mitochondrial fatty acid oxidation (FAO), carnitine palmitoyltransferase 2 (CPT2), glycolytic enzymes as well as energy-rich phosphates in HUVECs from uncomplicated term and preterm pregnancies were measured. Neonatal acylcarnitine profiles were analyzed postpartum. RESULTS Activities of RC complexes II+III, IV, V, and CS were higher in HUVECs from immature pregnancies. Overall FAO did not change, whereas CPT2 activity was higher in term neonates. RC complexes II-V and CS correlated inversely to gestational age, as well as CPT2 activity within the term cohort. Phosphofructokinase activity increased with maturation; lactate dehydrogenase and hexokinase as well as energy-rich phosphates remained constant. In blood, long-chain acylcarnitines were higher in term neonates. CONCLUSIONS Gestational age-dependent differences of energy-providing pathways in HUVECs were shown. Alterations of RC complexes with gestational age may be an adaptive process to cope with metabolic stress during birth; reduced oxidative phosphorylation and high glycolytic activity make HUVECs less susceptible to peripartum hypoxic damage. We hypothesize that HUVECs of premature neonates are metabolically maladapted to birth, which may be responsible for perinatal complications.