HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by PICKARD, G. E. Articles by SILVERMAN, A. J. Search for Related Content PubMed Articles by PICKARD, G. E. Articles by SILVERMAN, A. J.

Male hamsters were maintained on long (14 h light: 10 h darkness; 14L: 10D) or short (6L: 18D) photoperiods. Animals on short-days had reduced levels of LH in the serum and anterior pituitary gland, decreased androgen in the circulation and regressed testes and accessory sex organs. These same hamsters had significantly raised concentrations of hypothalamic luteinizing hormone releasing hormone (LH-RH). There was no significant difference in the response to exogenous LH-RH between groups maintained on long- and shortdays. Castration significantly reduced levels of LH-RH in the hypothalamus in the long-day animals but had little effect on this parameter in short-day animals which had already undergone testicular regression. The increased levels of LH-RH in the hypothalami of both intact and castrated hamsters on non-stimulatory photoperiods is interpreted as a decreased release of the neurohormone which subsequently results in a decreased release of LH.

This article has been cited by other articles:

				T. J. Greives, A. O. Mason, M.-A. L. Scotti, J. Levine, E. D. Ketterson, L. J. Kriegsfeld, and G. E. Demas Environmental Control of Kisspeptin: Implications for Seasonal Reproduction Endocrinology, March 1, 2007; 148(3): 1158 - 1166. [Abstract] [Full Text] [PDF]

				P.M. Collins, D.F. O'Neill, B.R. Barron, R.K. Moore, and N.M. Sherwood Gonadotropin-Releasing Hormone Content in the Brain and Pituitary of Male and Female Grass Rockfish (Sebastes rastrelliger) in Relation to Seasonal Changes in Reproductive Status Biol Reprod, July 1, 2001; 65(1): 173 - 179. [Abstract] [Full Text] [PDF]

				D. J. Bernard, R. Abuav-Nussbaum, T. H. Horton, and F. W. Turek Photoperiodic Effects on Gonadotropin-Releasing Hormone (GnRH) Content and the GnRH-Immunoreactive Neuronal System of Male Siberian Hamsters Biol Reprod, February 1, 1999; 60(2): 272 - 276. [Abstract] [Full Text] [PDF]

				M.H. Hastings, A.P. Walker, J.B. Powers, J. Hutchison, E.A. Steel, and J. Herbert Differential Effects of Photoperiodic History on the Responses of Gonadotrophins and Prolactin to Intermediate Daylengths in the Male Syrian Hamster J Biol Rhythms, September 1, 1989; 4(3): 335 - 350. [Abstract] [PDF]