title: Epidermal growth factor (EGF) produces inositol phosphates and increases cytoplasmic free calcium in cultured porcine thyroid cells.
abstract: The initial signal for thyroid cell proliferation is unknown. This is the first report to show that epidermal growth factor (EGF) produces inositol phosphates and increases cytoplasmic free calcium ([Ca2+]i) in the thyroid gland. In cultured porcine thyroid cells, 10 nM EGF produces a breakdown of phosphatidylinositol and stimulates inositol phosphate production. Ten nM EGF increases [Ca2+]i, measured using fura-2, a fluorescent Ca2+ indicator; the EGF-induced [Ca2+]i response occurs immediately, reaches a maximum within several seconds, and then slowly declines. EGF stimulates production of inositol phosphates, which seem to increase [Ca2+]i. Inositol phosphate production and an increase in [Ca2+]i after EGF-stimulation may function as an initial signal for thyroid cell proliferation.
authors.affiliation: Department of Gerontology, Endocrinology and Metabolism, School of Medicine, Shinshu University, Nagano-ken, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Takasu
authors.forename: M
authors.initials: M
authors.lastname: Takasu
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: Y
authors.initials: Y
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D007295:Inositol Phosphates / Q000378:metabolism*; D013403:Sugar Phosphates / Q000378:metabolism*; D013552:Swine; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D007295:Inositol Phosphates; D013403:Sugar Phosphates; D004815:Epidermal Growth Factor; D002118:Calcium