Effects of arachidonic acid on RNA metabolism in mammary gland explants of mice.

Arachidonic acid stimulated 3H-uridine incorporation into RNA in mammary gland explants of mice in a manner similar to that of prolactin. The onset of the effects of both prolactin and arachidonic acid occurred following a 2-4 hour lag period. Further, effects of maximally stimulatory concentrations of these agents were nonadditive. Finally, indomethacin abolished the effects of both prolactin and arachidonic acid. A tenable hypothesis to explain these data is that the action of prolactin in the mammary gland may be mediated by an increased availability of arachidonic acid followed by a subsequent enhanced rate of formation of the prostaglandins.