title: Estradiol stimulates in vitro the secretion of insulin-like growth factors by the clonal osteoblastic cell line, UMR106.
abstract: UMR106 cells, a rat osteosarcoma derived clonal line, secreted insulin-like growth factors (IGF) in vitro. The IGF-II levels corrected for the cell numbers were 7-8 times higher than the IGF-I levels in the medium. Both growth factors were higher by 4-5 fold in medium conditioned by rapidly growing cells than in medium conditioned by confluent cells. The addition of 17-beta-estradiol (E) to the culture medium was associated with a statistically significant increase in the IGF concentrations. This increment was metabolite specific, not occurring with 17-alpha-E, the inactive epimer of E. 1,25(OH)2D3 also increased the IGF-I concentration but prior treatment with E blocked the response to 1,25(OH)2D3, demonstrating antagonistic actions of these two hormones on IGF secretion by osteoblast-like cells.
authors.affiliation: Department of Medicine, University of North Carolina, Chapel Hill 27599-7170.
authors.forename: T K
authors.initials: TK
authors.lastname: Gray
authors.forename: S
authors.initials: S
authors.lastname: Mohan
authors.forename: T A
authors.initials: TA
authors.lastname: Linkhart
authors.forename: D J
authors.initials: DJ
authors.lastname: Baylink
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D066298:In Vitro Techniques; D010006:Osteoblasts / Q000378:metabolism*; D012516:Osteosarcoma; D051381:Rats; D013002:Somatomedins / Q000378:metabolism*; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D013002:Somatomedins; D004958:Estradiol; D002117:Calcitriol