Observations on the Early Actions of Prolactin on RNA and Casein Synthesis in Mouse Mammary Gland Explants

Abstract

The action of prolactin on RNA synthesis in cultured mouse mammary gland explants becomes manifest when the tissues are exposed only briefly (1 h or less) to prolactin. In contrast, the action of prolactin on casein synthesis only becomes apparent when the tissues are cultured for 6 h or more with prolactin. Once the actions of prolactin on RNA and casein synthesis are initiated, however, these effects persist for hours or days, even when the tissues are subsequently cultured in the absence of prolactin.

Unexpected severe consequences ofPikfyvedeletion by aP2- or Aq-promoter-driven Cre expression for glucose homeostasis and mammary gland development

“…To delineate if PIKfyve's role in mammary gland development during pregnancy and lactation is mechanistically linked with the PrlR signaling pathway, we used mammary gland explants derived from midpregnant female mice, an ex vivo system that we have previously developed and characterized with respect to prolactin‐induced milk protein production (Rillema and Schneider‐Kuznia ; Rillema ). Subsequent to 24 h culturing in media containing insulin and cortisol, mammary gland explants were treated with or without prolactin (Prl) for additional 24 h. As illustrated in Figure A and B, Prl profoundly increased PIKfyve protein levels as revealed by western blotting with anti‐PIKfyve antibodies, with or without prior immunoprecipitation.…”