title: Regulation of insulin-like growth factor messenger ribonucleic acid in rat growth plate by growth hormone.
abstract: The mechanism of action for the stimulatory effect of GH on longitudinal bone growth is not yet clarified. Several recent reports indicate that GH has a direct effect at the site of the epiphyseal growth plate, as opposed to the somatomedin hypothesis which holds that the effect of GH is mediated by circulating insulin-like growth factors (IGFs). Using a RNA probe in a solution hybridization assay we investigated the presence of IGF-I mRNA in rat rib growth plate. Hypophysectomy resulted in a decrease in the number of IGF-I mRNA copies compared to that in normal rats. Replacement treatment with GH restored the number of transcripts in a specific and dose-dependent manner. The results show that GH regulates the level of IGF-I mRNA in rat rib growth plate and give further support to the hypothesis that locally produced IGF-I might contribute to the stimulatory effect of GH on longitudinal bone growth.
authors.affiliation: Department of Physiology, University of Göteborg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Isgaard
authors.forename: C
authors.initials: C
authors.lastname: Möller
authors.forename: O G
authors.initials: OG
authors.lastname: Isaksson
authors.forename: A
authors.initials: A
authors.lastname: Nilsson
authors.forename: L S
authors.initials: LS
authors.lastname: Mathews
authors.forename: G
authors.initials: G
authors.lastname: Norstedt
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D002356:Cartilage / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004838:Epiphyses / Q000187:drug effects / Q000378:metabolism*; D013006:Growth Hormone / Q000494:pharmacology*; D007016:Hypophysectomy; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000235:genetics*
chemical_list: D000199:Actins; D012333:RNA, Messenger; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D004247:DNA