Gonadotrophin-Inhibitory Hormone in the Cichlid Fish Cichlasoma dimerus: Structure, Brain Distribution and Differential Effects on the Secretion of Gonadotrophins and Growth Hormone

M. P. Di Yorio, D. I. Pérez Sirkin, T. H. Delgadin, A. Shimizu, Kazuyoshi Tsutsui, G. M. Somoza, P. G. Vissio*

*この研究の対応する著者

    研究成果: Article査読

    34 被引用数 (Scopus)

    抄録

    The role of gonadotrophin-inhibitory hormone (GnIH) in the inhibition of the reproductive axis has been well-established in birds and mammals. However, its role in other vertebrates, such as the teleost fish, remains controversial. In this context, the present study aimed to evaluate whether GnIH modulates the release of gonadotrophins and growth hormone (GH) in the cichlid fish Cichlasoma dimerus. First, we partially sequenced the precursor polypeptide for GnIH and identified three putative GnIH peptides. Next, we analysed the expression of this precursor polypeptide via a polymerase chain reaction in the reproductive axis of both sexes. We found a high expression of the polypeptide in the hypothalamus and gonads of males. Immunocytochemistry allowed the observation of GnIH-immunoreactive somata in the nucleus posterioris periventricularis and the nucleus olfacto-retinalis, with no differences between the sexes. GnIH-immunoreactive fibres were present in all brain regions, with a high density in the nucleus lateralis tuberis and at both sides of the third ventricle. Finally, we performed in vitro studies on intact pituitary cultures to evaluate the effect of two doses (10−6 m and 10−8 m) of synthetic C. dimerus (cd-) LPQRFa-1 and LPQRFa-2 on the release of gonadotrophins and GH. We observed that cd-LPQRFa-1 decreased β-luteinising hormone (LH) and β-follicle-stimulating hormone (FSH) and also increased GH release to the culture medium. The release of β-FSH was increased only when it was stimulated with the higher cd-LPQRFa-2 dose. The results of the present study indicate that cd-LPQRFa-1, the cichlid fish GnIH, inhibits β-LH and β-FSH release and stimulates GH release in intact pituitary cultures of C. dimerus. The results also show that cd-LPQRF-2 could act as an β-FSH-releasing factor in this fish species.

    本文言語English
    ジャーナルJournal of Neuroendocrinology
    28
    5
    DOI
    出版ステータスPublished - 2016 5 1

    ASJC Scopus subject areas

    • 内分泌学、糖尿病および代謝内科学
    • 内分泌学
    • 内分泌系および自律システム
    • 細胞および分子神経科学

    フィンガープリント

    「Gonadotrophin-Inhibitory Hormone in the Cichlid Fish Cichlasoma dimerus: Structure, Brain Distribution and Differential Effects on the Secretion of Gonadotrophins and Growth Hormone」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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