title: Further characterization of the inhibition of casein production in a primary mouse mammary epithelial cell culture by epidermal growth factor. Antagonism by cyclic AMP.
abstract: Epidermal growth factor (EGF) inhibited casein production and the accumulation of casein mRNA activity induced by insulin (I), cortisol (F) and prolactin (P) in a primary culture of mammary epithelial cells from pregnant mice. The inhibitory effects of EGF were blocked by 8-bromo cyclic AMP (8-br-cAMP) in a dose-dependent manner. The effect of 8-br-cAMP was observed at a concentration as low as 20 microM and was maximal at 500 microM. Dibutyryl cyclic AMP (db-cAMP), cAMP, and 3-isobutylmethylxanthine (IBMX), an inhibitor of phosphodiesterase, also antagonized the inhibitory effect of EGF on casein production. 8-Br-cAMP had, however, no effect on the mitogenic activity of EGF in this system. These results suggest a possible modulatory role of cAMP in EGF-induced inhibition of casein production in cultured mammary epithelial cells.
authors.forename: M
authors.initials: M
authors.lastname: Arakawa
authors.forename: J W
authors.initials: JW
authors.lastname: Perry
authors.forename: M F
authors.initials: MF
authors.lastname: Cossu
authors.forename: T
authors.initials: T
authors.lastname: Oka
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D002364:Caseins / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors*; D004848:Epithelium / Q000378:metabolism; D005260:Female; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors
chemical_list: D002364:Caseins; D012333:RNA, Messenger; D015124:8-Bromo Cyclic Adenosine Monophosphate; D004815:Epidermal Growth Factor; D004247:DNA; D000242:Cyclic AMP