Effect of glucose load on the transport kinetics of palmitic acid in the human placenta: An in vitro study

1. A paucity of data relating to free fatty acid (FFA) transport in the hum an placenta in non-steady state conditions prompted us to undertake the pre sent study. 2. The transport kinetics of palmitic acid in non-steady state conditions h ave been investigated in vitro using human perfused placental lobules, The effects of varying glucose concentrations on maternal-foetal transport of t he FFA were also investigated to mimic the hyperglycaemic states of human d iabetic pregnancies, 3. National Cancer Tissue Culture medium diluted with Earle's buffered salt solution was used as the perfusate, [C-14]-Palmitic acid, along with triti ated water as a reference, was injected as a bolus into the maternal arteri al perfusate and perfusate samples were collected from the venous outflow f or a period of 5 min, 4. The transport fraction (TF) of palmitic acid, expressed as percentage of the injected bolus, averaged 3.45+/-0.15% in five perfusions, representing 9.2+/-1.3% of the corresponding reference marker TF, Kinetic parameters, a s well as TF indices of palmitic acid expressed in relation to the referenc e substance, did not differ significantly between perfusions with a physiol ogical glucose load and those with hyperglycaemic concentrations of glucose of 27.8 and 55.6 mmol/L. 5. The present study shows that hyperglycaemia per se does not significantl y alter palmitic acid transport kinetics in vitro in the human perfused pla cental lobule.