O2 consumption in the in-vitro fetal side human placenta.
The relative dependence of placental O2 consumption (MO2) on O2 supply (SupO2) parameters, and the fraction of aerobic O2 utilization, was studied by in-vitro perfusion of the fetal side of term human placental lobes. Placental MO2 was a function of the combined effect of SupO2 parameters (PO2, perfusate flow rate, perfusate effective O2 solubility) and not of each separately. At SupO2 greater than 800 microliters/(min.lobe), MO2 saturated at 260 microliters/(min.lobe). No accumulation of O2 debt could be detected even after 2 h anoxia. Adding CN- or CO to perfusate did not abolish MO2, and a residual MO2 of 31-37% of control MO2 was measured. In its MO2, the placenta is a typical conformer tissue. This conformity enables conservation of O2 transfer to the embryo even when placental SupO2 is radically reduced. Only about 60-70% of placental MO2 is utilized in the aerobic respiratory pathway, while about 30-40% of the oxygen is used in other pathways.
Mover-Lev
H
H
Department of Bioengineering, Faculty of Engineering, Tel-Aviv University, Ramat Aviv, Israel.
Dreval
D
D
Zakut
H
H
Ar
A
A
D001682:Biological Availability; D002248:Carbon Monoxide / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D005260:Female; D005333:Fetus; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology; D066298:In Vitro Techniques; D010100:Oxygen / Q000493:pharmacokinetics; D010101:Oxygen Consumption / Q000187:drug effects; D010477:Perfusion; D010920:Placenta / Q000187:drug effects / Q000378:metabolism*; D011247:Pregnancy
D003486:Cyanides; D002248:Carbon Monoxide; D010100:Oxygen