This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ubuka, T. Articles by Tsutsui, K. Search for Related Content PubMed PubMed Citation Articles by Ubuka, T. Articles by Tsutsui, K.

Gonadotropin-Inhibitory Hormone Inhibits Gonadal Development and Maintenance by Decreasing Gonadotropin Synthesis and Release in Male Quail

Laboratory of Brain Science (T.U., K.U., K.T.), Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan; Core Research for Evolutional Science and Technology (T.U., K.U., K.T.), Japan Science and Technology Corporation, Tokyo 150-0002, Japan; Division of Genetics and Genomics (P.J.S.), Roslin Institute, Midlothian, EH25 9PS, United Kingdom; and Department of Integrative Biology (G.E.B.), University of California, Berkeley, California 94720

Address all correspondence and requests for reprints to: Kazuyoshi Tsutsui, Laboratory of Brain Science, Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan. E-mail: tsutsui{at}hiroshima-u.ac.jp

Until recently, any neuropeptide that directly inhibits gonadotropin secretion had not been identified. We recently identified a novel hypothalamic dodecapeptide that directly inhibits gonadotropin release in quail and termed it gonadotropin-inhibitory hormone (GnIH). The action of GnIH on the inhibition of gonadotropin release is mediated by a novel G protein-coupled receptor in the quail pituitary. This new gonadotropin inhibitory system is considered to be a widespread property of birds and provides us with an unprecedented opportunity to study the regulation of avian reproduction from an entirely novel standpoint. To understand the physiological role(s) of GnIH in avian reproduction, we investigated GnIH actions on gonadal development and maintenance in male quail. Continuous administration of GnIH to mature birds via osmotic pumps for 2 wk decreased the expressions of gonadotropin common and LHß subunit mRNAs in a dose-dependent manner. Plasma LH and testosterone concentrations were also decreased dose dependently. Furthermore, administration of GnIH to mature birds induced testicular apoptosis and decreased spermatogenic activity in the testis. In immature birds, daily administration of GnIH for 2 wk suppressed normal testicular growth and rise in plasma testosterone concentrations. An inhibition of juvenile molt also occurred after GnIH administration. These results indicate that GnIH inhibits gonadal development and maintenance through the decrease in gonadotropin synthesis and release. GnIH may explain the phenomenon of photoperiod-induced gonadal regression before an observable decline in hypothalamic GnRH in quail. To our knowledge, GnIH is the first identified hypothalamic neuropeptide inhibiting reproductive function in any vertebrate class.

This article has been cited by other articles:

				I. J. Clarke, I. P. Sari, Y. Qi, J. T. Smith, H. C. Parkington, T. Ubuka, J. Iqbal, Q. Li, A. Tilbrook, K. Morgan, et al. Potent Action of RFamide-Related Peptide-3 on Pituitary Gonadotropes Indicative of a Hypophysiotropic Role in the Negative Regulation of Gonadotropin Secretion Endocrinology, November 1, 2008; 149(11): 5811 - 5821. [Abstract] [Full Text] [PDF]

				J. T. Smith, L. M. Coolen, L. J. Kriegsfeld, I. P. Sari, M. R. Jaafarzadehshirazi, M. Maltby, K. Bateman, R. L. Goodman, A. J. Tilbrook, T. Ubuka, et al. Variation in Kisspeptin and RFamide-Related Peptide (RFRP) Expression and Terminal Connections to Gonadotropin-Releasing Hormone Neurons in the Brain: A Novel Medium for Seasonal Breeding in the Sheep Endocrinology, November 1, 2008; 149(11): 5770 - 5782. [Abstract] [Full Text] [PDF]

				E. M. Gibson, S. A. Humber, S. Jain, W. P. Williams III, S. Zhao, G. E. Bentley, K. Tsutsui, and L. J. Kriegsfeld Alterations in RFamide-Related Peptide Expression Are Coordinated with the Preovulatory Luteinizing Hormone Surge Endocrinology, October 1, 2008; 149(10): 4958 - 4969. [Abstract] [Full Text] [PDF]

				T. Ubuka, N. L. McGuire, R. M. Calisi, N. Perfito, and G. E. Bentley The control of reproductive physiology and behavior by gonadotropin-inhibitory hormone Integr. Comp. Biol., April 27, 2008; (2008) icn019v1. [Abstract] [Full Text] [PDF]

				V. S. Chowdhury, K. Yamamoto, I. Saeki, I. Hasunuma, T. Shimura, and K. Tsutsui Melatonin Stimulates the Release of Growth Hormone and Prolactin by a Possible Induction of the Expression of Frog Growth Hormone-Releasing Peptide and Its Related Peptide-2 in the Amphibian Hypothalamus Endocrinology, March 1, 2008; 149(3): 962 - 970. [Abstract] [Full Text] [PDF]

				S. R Maddineni, O. M Ocon-Grove, S. M Krzysik-Walker, G. L Hendricks III, and R. Ramachandran Gonadotropin-inhibitory hormone (GnIH) receptor gene is expressed in the chicken ovary: potential role of GnIH in follicular maturation Reproduction, February 1, 2008; 135(2): 267 - 274. [Abstract] [Full Text] [PDF]

				T. Ubuka, S. Kim, Y.-c. Huang, J. Reid, J. Jiang, T. Osugi, V. S. Chowdhury, K. Tsutsui, and G. E. Bentley Gonadotropin-Inhibitory Hormone Neurons Interact Directly with Gonadotropin-Releasing Hormone-I and -II Neurons in European Starling Brain Endocrinology, January 1, 2008; 149(1): 268 - 278. [Abstract] [Full Text] [PDF]