Mechanism of action of TNF-α-stimulated prostaglandin production in cultured bovine luteal cells

Tumor necrosis factor-alpha (TNF-α) influences hormone synthesis of many ovarian cell types and can also exert cytotoxic effects, possibly by increasing the synthesis of prostaglandins. The purpose of the present study was to characterize the mechanism of TNF-α-stimulated prostaglandin F(2α) (PGF(2α)) production in cultured bovine luteal cells. Inhibitors of RNA and protein synthesis (actinomycin D and cycloheximide, respectively) completely blocked TNF-α-stimulated PGF(2α) production. The phospholipase A₂ inhibitor, aristolochic acid, prevented TNF-α-stimulated, but not basal, PGF(2α) production, whereas the phospholipase C inhibitor, compound 48/80, was without effect. The addition of arachidonic acid to cultures did not overcome the inhibitory effects of cycloheximide or aristolochic acid. In conclusion, TNF-α-stimulated prostaglandin production by bovine luteal cells is dependent upon the stimulation of phospholipase A₂ through mechanisms which require synthesis of RNA and protein.