Inhibition of Prolactin Actions in Mouse Mammary Gland Explants by p -Bromphenacyl Bromide,a Phospholipase A 2 Inhibitor 1

Summary

The stimulatory actions of prolactin on RNA and casein synthesis in mouse mammary gland explants were shown to be significantly reduced or abolished by incubation with p-bromphenacyl bromide (BPB) at concentrations of 0.05 mM or greater. Since BPB has been shown to be an inhibitor of phospholipase A₂ activity, the inhibition of prolactin's actions by BPB provides further support for the proposal that at least certain of the actions of prolactin in the mammary gland may be initiated by a stimulation of membrane-associated phospholipase A₂ activity.