title: Inhibitory effect of 17 beta -estradiol on prostaglandin E2-induced phosphoinositide hydrolysis in osteoblast-like cells.
abstract: We examined the effect of estradiol on PGE2-induced phosphoinositide hydrolysis and cAMP production in cloned osteoblast-like MC3T3-E1 cells. 17 beta -Estradiol pretreatment significantly inhibited the formation of inositol phosphates induced by 10 microM PGE2 in a dose-dependent manner between 1 pM and 10 nM. This effect of 17 beta -estradiol was dependent on the time of pretreatment and submaximum inhibition was observed at 4 h. However, 17 beta -estradiol had little effect on the formation of inositol phosphates induced by 20 mM NaF, a GTP-binding protein activator. The cAMP production induced by PGE2 was not influenced by 17 beta -estradiol. These results suggest that 17 beta -estradiol modulates the signal transduction by PGE2 and that the effect seems to be exerted between PGE2 receptor and the GTP-binding protein coupled to phospholipase C in osteoblast-like MC3T3-E1 cells.
authors.affiliation: First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tokuda
authors.forename: M
authors.initials: M
authors.lastname: Yoneda
authors.forename: Y
authors.initials: Y
authors.lastname: Oiso
authors.forename: O
authors.initials: O
authors.lastname: Kozawa
mesh_terms: D000818:Animals; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis; D015232:Dinoprostone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000502:physiology; D006868:Hydrolysis; D007295:Inositol Phosphates / Q000378:metabolism*; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D012969:Sodium Fluoride / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D007295:Inositol Phosphates; D004958:Estradiol; D012969:Sodium Fluoride; D000242:Cyclic AMP; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D015232:Dinoprostone