Role of protein kinase C in the prolactin-induced responses in mouse mammary gland explants.
Recently, the protein kinase C (PKC) activator 12-O-tetradecanoylphorbol 13-acetate (TPA) was found to have prolactin (PRL)-like actions on specific metabolic processes in mouse mammary gland explants. Since TPA is known to stimulate PKC, these observations suggest that PKC may have a role in the PRL stimulation of lactogenic processes. The present studies provide further evidence for this by demonstrating a transient, time-dependent translocation of PKC to the particulate fraction in response to PRL. Particulate-associated PKC reached a maximum between 15-30 min and returned to control values within 1-2 h after PRL treatment. PRL treatment for 16 h also induced a down-regulation of total cellular PKC. Inhibition of PKC function, either by a 30 h pretreatment with TPA (PKC down-regulation) or 2 h with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7), resulted in an attenuation of PRL-stimulated effects on ornithine decarboxylase activity and synthesis of RNA, caseins, and lipids.
Waters
S B
SB
Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201.
Rillema
J A
JA
D000818:Animals; D002478:Cells, Cultured; D005260:Female; D008321:Mammary Glands, Animal / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D051379:Mice; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology*; D011493:Protein Kinase C / Q000032:analysis / Q000502:physiology*
D011388:Prolactin; D011493:Protein Kinase C