This Article Full Text Full Text (PDF) All Versions of this Article: 147/11/5069    most recent Author Manuscript (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 Kauffman, A. S. Articles by Rissman, E. F. Search for Related Content PubMed PubMed Citation Articles by Kauffman, A. S. Articles by Rissman, E. F.

Gonadotropin-Releasing Hormone-II Messenger Ribonucleic Acid and Protein Content in the Mammalian Brain Are Modulated by Food Intake

Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia 22908

Address all correspondence and requests for reprints to: Dr. Alexander S. Kauffman, Department of Physiology and Biophysics, Health Sciences Building, Box 357290, University of Washington, Seattle, Washington 98195. E-mail: ask47{at}u.washington.edu.

GnRH-II is the most evolutionarily conserved member of the GnRH peptide family. In mammals, GnRH-II has been shown to regulate reproductive and feeding behaviors. In female musk shrews, GnRH-II treatment increases mating behaviors and decreases food intake. Although GnRH-II-containing neurons are known to reside in the midbrain, the neural sites of GnRH-II action are undetermined, as is the degree to which GnRH-II is regulated by energy availability. To determine whether GnRH-II function is affected by changes in food intake, we analyzed the levels of GnRH-II mRNA in the midbrain and GnRH-II protein in numerous target regions. Adult musk shrews were ad libitum fed, food restricted, or food restricted and refed for varying durations. Compared with ad libitum levels, food restriction decreased, and 90 min of refeeding reinstated, GnRH-II mRNA levels in midbrain and GnRH-II peptide in several target areas including the medial habenula and ventromedial nucleus. Refeeding for 90 min also reinstated female sexual behavior in underfed shrews. In male shrews, abundant GnRH-II peptide was present in all sites assayed, including the preoptic area, a region with only low GnRH-II in females. In contrast to females, food restriction did not affect GnRH-II protein in male brains or inhibit their mating behavior. Our results further define the relationship between GnRH-II, energy balance, and reproduction, and suggest that food restriction may inhibit female reproduction by reducing GnRH-II output to several brain nuclei. We postulate that this highly conserved neuropeptide functions similarly in other mammals, including humans, to fine-tune reproductive efforts with periods of sufficient energy resources.

This article has been cited by other articles:

				J. S. Schneider and E. F. Rissman Gonadotropin-releasing hormone II: A multi-purpose neuropeptide Integr. Comp. Biol., April 19, 2008; (2008) icn018v1. [Abstract] [Full Text] [PDF]