Synthesis, turnover and compartment analysis of the free fatty acids in the placenta of rats.

The in vivo tracer method and in vitro acetate incorporation experiments were used to investigate the metabolism of placental free fatty acids. Analysis of data revealed that free fatty acids pass into the fetus from maternal plasma through a small placental compartment, which accounts for only 5 percent of all of the placental free fatty acids. The turnover time of this compartment is 0.57 min. The rate of placental fatty acid synthesis evaluated by both methods is very small and amounts to 0.003 mumols fatty acids/min/all placentas of one litter.