Transport of radioactive deoxyglucose by the isolated perfused human placental cotyledon as measured by the paired-tracer dilution method. Inconsistency of the transfer rates across the two trophoblast borders with the simultaneously measured rate of transplacental transfer.
The uptake of [3H]2-deoxy-D-glucose ([3H]2DG) by the maternal and fetal borders of the trophoblast was measured in the dually perfused human placental cotyledon by use of the paired-tracer dilution method. The uptake was estimated from the maximum extraction of the tracer. The transcellular component of transplacental transport of [3H]2DG was measured simultaneously. From the rates of uptake by the two trophoblast borders the rate of transcellular transport was predicted. The rate predicted was significantly lower than the rate observed. This was taken to indicate that the paired-tracer dilution method based on the maximum extraction underestimated the rates of uptake.
D001692:Biological Transport; D002250:Carbon Radioisotopes; D003837:Deoxy Sugars / Q000493:pharmacokinetics*; D003847:Deoxyglucose / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008431:Maternal-Fetal Exchange; D010477:Perfusion; D011247:Pregnancy; D011865:Radioisotope Dilution Technique; D014316:Tritium; D014327:Trophoblasts / Q000378:metabolism*
D002250:Carbon Radioisotopes; D003837:Deoxy Sugars; D014316:Tritium; D003847:Deoxyglucose