Oxygen consumption in human placental lobules in vitro (survival maintained by perfusion)]

The average oxygen utilization coefficient of 26% is calculated from PO2 determinations during the perfusion of the fetal circulation of isolated human term placental lobules. The oxygen consumption approximates 0.4 ml/min/kg placenta when Earle's salt solution is used as a perfusion medium and is equilibrated with a gas mixture containing 5% O2. The oxygen consumption reaches 2 ml/min/kg when the same Earle's solution is equilibrated with a gas mixture containing 95% O2.