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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >
Stimulatory effects of insulin-like growth factor 1 on expression of gonadotropin subunit genes and release of follicle-stimulating hormone and luteinizing hormone in masu salmon pituitary cells early in gametogenesis
| Title: | Stimulatory effects of insulin-like growth factor 1 on expression of gonadotropin subunit genes and release of follicle-stimulating hormone and luteinizing hormone in masu salmon pituitary cells early in gametogenesis |
| Authors: | Furukuma, Shunji Browse this author | | Onuma, Takeshi Browse this author | | Swanson, Penny Browse this author | | Luo, Qiong Browse this author | | Koide, Nobuhisa Browse this author | | Okada, Houji Browse this author | | Urano, Akihisa Browse this author | | Ando, Hironori Browse this author |
| Keywords: | insulin-like growth factor 1 | | gonadotropin-releasing hormone | | gonadotropin | | pituitary | | puberty | | salmon |
| Issue Date: | Jan-2008 |
| Publisher: | Zoological Society of Japan |
| Journal Title: | Zoological Science |
| Volume: | 25 |
| Issue: | 1 |
| Start Page: | 88 |
| End Page: | 98 |
| Publisher DOI: | 10.2108/zsj.25.88 |
| Abstract: | Insulin-like growth factor-I (IGF-I) has been shown to be involved in pubertal activation of gonadotropin (GTH) secretion. The aim of this study was to determine if IGF-I directly stimulates synthesis and release of GTH at an early stage of gametogenesis. The effects of IGF-I on expression of genes encoding glycoprotein α (GPα), follicle-stimulating hormone (FSH) β, and luteinizing hormone (LH) β subunits and release of FSH and LH were examined using primary pituitary cells of masu salmon at three reproductive stages: early gametogenesis, maturing stage, and spawning. IGF-I alone or IGF-I + salmon GnRH (sGnRH) were added to the primary pituitary cell cultures. Amounts of GPα, FSHβ, and LHβ mRNAs were determined by real-time PCR. Plasma and medium levels of FSH and LH were determined by RIA. In males, IGF-I increased the amounts of all three subunit mRNAs early in gametogenesis in a dose-dependent manner, but not in the later stages. In females, IGF-I stimulated release of FSH and LH early in gametogenesis, whereas no stimulatory effects on the subunit mRNA levels were observed at any stage. IGF-I + sGnRH stimulated release of FSH and LH at all stages in both sexes, but had different effects on the subunit mRNA levels depending on subunit and stage. The present results suggest that IGF-I itself directly stimulates synthesis and release of GTH early in gametogenesis in masu salmon, possibly acting as a metabolic signal that triggers the onset of puberty. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/43960 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 浦野 明央
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