We have investigated the role of phospholipid-sensitive calcium-dependent protein kinase (protein kinase C) in prostaglandin F2 alpha synthesis by monolayer cultures of swine granulosa cells. In this system, specific phorbol ester derivatives known to activate protein kinase C significantly augmented the production of prostaglandin F2 alpha. Phorbol ester in conjunction with the ionophore A23187 synergistically increased prostaglandin F2 alpha production. These stimulatory actions were dose- and time-dependent, and could be abolished by the cyclooxygenase inhibitor, indomethacin, or the protein synthesis inhibitor, cycloheximide. Moreover, the rank order of potency of phorbol esters in enhancing prostaglandin F2 alpha production was concordant with that demonstrated for activation of protein kinase C in the swine ovary. In addition, a nonphorbol stimulator of protein kinase C, 1-octanoyl-2-acetylglycerol, also significantly enhanced prostaglandin F2 alpha biosynthesis. The synthesis of immunoassayable prostaglandin F2 alpha was confirmed by high-pressure liquid chromatographic purification of this radiolabeled metabolite of [3H]arachidonic acid. Thus, the present studies indicate that the protein kinase C effector pathway in the swine granulosa cell is functionally coupled to prostaglandin F2 alpha production.