Effect of alpha-fetoprotein on arachidonic acid metabolism in the preadipocyte cell line OB 17.

Previous work has shown that alpha-fetoprotein (AFP) is able to bind specifically polyunsaturated fatty acids, one of the major ligands being arachidonic acid (C20:4). In the present study, we demonstrate that AFP is able to reduce the metabolism of exogenous C20:4 by ob17 cells. Both prostaglandins and lipoxygenase products formation were reduced when cells were maintained in the presence of AFP. This decrease was counterbalanced by a higher release of C20:4 into the culture medium by the cells. The amount of C20:4 incorporated into cellular lipids was decreased but the distribution of C20:4 in the different lipid classes remained unchanged. The modification of C20:4 metabolism by AFP might be of primordial importance in developmental biology and may shed a new light on the physiological actions of AFP which have been described in the past years such as ovarian inhibition, cell growth control and immuno-suppressive activity.