Effect of NDGA, a lipoxygenase inhibitor, on prolactin actions in mouse mammary gland explants.

Nordihydroguaiaretic acid (NDGA) at a concentration of 50 microM abolished the actions of prolactin on RNA, casein and lipid biosynthesis in cultured mouse mammary gland explants. NDGA at 100 microM also reduced the magnitude of the prolactin stimulation of ornithine decarboxylase activity. Since NDGA is known to be an inhibitor of lipoxygenase activity, we would conclude that ongoing leukotriene synthesis may be essential for prolactin to express at least certain of its lactogenic actions in the mammary gland.