Movatterモバイル変換

[0]ホーム
URL:

Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
Thehttps:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log inShow account info
Access keysNCBI HomepageMyNCBI HomepageMain ContentMain Navigation
pubmed logo
Advanced Clipboard
User Guide

Actions

Share

Review
.2004;198(1):53-60.

[Gonadotrophin-releasing hormone (GnRH) in the animal kingdom]

[Article in French]
Affiliations
  • PMID:15146956
Review

[Gonadotrophin-releasing hormone (GnRH) in the animal kingdom]

[Article in French]
Olivier Kah et al. J Soc Biol.2004.

Abstract

As a major actor of the brain-pituitary-gonad axis, GnRH has received considerable attention, mainly in vertebrates. Biochemical, molecular, neuroanatomical, pharmacological and physiological studies have mainly focused on the role of GnRH as a gonadotrophin-releasing factor and have led to a detailed knowledge of the hypophysiotrophic GnRH system, primarily in mammals, but also in fish. It is now admitted that the corresponding neurons develop from the olfactory epithelium and migrate into the forebrain during embryogenesis to establish connections with the median eminence in tetrapods or the pituitary in teleost fish. However, all vertebrates possess a second GnRH system, expressing a variant known as chicken GnRH-II in neurons of the synencephalon, whose functions are still under debate. In addition, many fish species express a third form, salmon GnRH, whose expression is restricted to neurons of the olfactory systems and the ventral telencephalon, with extensive projections in the brain and a minor contribution to the pituitary. In vertebrates, GnRHs are also expressed in the gonads where they act on cell proliferation and steroidogenesis in males, and apoptosis of granulosa cells and reinititaion of meiosis in females. These functions could possibly represent the primitive roles of GnRH-like peptides, as an increasing number of studies in invertebrate classes point to a more or less direct connection between GnRH-producing sensory neurons and the gonads. According to recent studies, GnRHs appear as very ancient peptides that emerged at least in the cnidarians, the first animals with a nervous system. GnRH-like peptides have been partially characterized in several classes of invertebrates notably in molluscs, echinoderms and prochordates in which effects on the reproductive functions, notably gamete release and steroidogeneis, have been evidenced. It is possible that, with the increasing complexity of metozoa, GnRH neurons have lost their direct connection with the gonad to specialize in the control of additional regulatory centers such as the hypophysis in vertebrates or the optic gland in cephalopods. However, reminiscent effects of GnRH functions at the gonadal level would have persisted due to local production of GnRHs in the gonad itself. Altogether, these data indicate that GnRHs were involved in the control of reproduction long before the appearance of pituitary gonadotrophs.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

MeSH terms

Substances

Related information

LinkOut - more resources

Cite
Send To

NCBI Literature Resources

MeSHPMCBookshelfDisclaimer

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

[8]ページ先頭
©2009-2025 Movatter.jp