The effect of vanadate of arachidonic acid metabolism in human amnion cells.

This investigation was designed to investigate the effects of vanadate on arachidonic acid metabolism in human amnion cell in primary monolayer culture that served as a model system. The secretion of prostaglandin E2 (PGE2) into the culture medium was quantified by radioimmunoassay. The rate of conversion of [14C] arachidonic acid to [14C] PGE2 (PGE2 synthase) was determined in cell sonicates under optimal in vitro conditions. A maximal stimulation of PGE2 production and PGE2 synthase activity was determined with vanadate at a concentration of 32 microM) was effective maximally after 4 h of treatment, i.e., the production of PGE2 was stimulated 2,3-fold, and the specific activity of PGE2 synthase 2,1-fold compared with control incubations, respectively. We suggest that vanadate acts to increase the rate of conversion of arachidonic acid to PGE2 by a mechanism that involves de novo protein synthesis or that alters the phosphorylation state of enzymes that are requisite for the conversion of arachidonic acid to PGE2.