Elsevier

Brain Research

Volume 898, Issue 1, 13 April 2001, Pages 166-170
Brain Research

Short communication
A significant participation of orexin-A, a potent orexigenic peptide, in the preovulatory luteinizing hormone and prolactin surges in the rat

https://doi.org/10.1016/S0006-8993(01)02157-6Get rights and content

Abstract

Orexins are novel hypothalamic peptides which stimulate food intake. In view of the well-known tight connection between the nutritional state and the reproductive function, in this study we examined a possible role of orexin-A in the generation of ovarian steroid-induced luteinizing hormone (LH) and prolactin (PRL) surges in ovariectomized rats. Experiments were performed on both normally-fed and 3-day-fasted rats. Although fasting led to abolition of both LH and PRL surges, intracerebroventricular administration of orexin-A (0.3 and 3.0 nmol) resulted in a dose-dependent recovery of the hormonal surges. In addition, anti-orexin-A antisera given to normally-fed rats completely abrogated the surges of both hormones. These results demonstrate for the first time a significant participation of orexin-A in the preovulatory LH and PRL surges in the rat.

Section snippets

Acknowledgements

We wish to thank the National Hormone and Pituitary Program of NIDDK and Dr. A.F. Parlow for the generous donation of reagents for rat PRL and LH RIAs. Helgi B. Schiöth was supported by the Swedish Society for Medical Research and the Åke Wiberg foundation.

Cited by (96)

  • Orexin A enhances food intake in bullfrog larvae

    2014, Peptides
    Citation Excerpt :

    The orexin receptor has been found to have two forms: orexin receptors 1 and 2 (OX1R and OX2R) [27,34,43]. In mammals including human beings and rodents, orexin also controls multiple brain functions including emotional behavior and rhythmicity such as the sleep-wakefulness cycle in addition to appetite [4,9,10,13,25–28,36,42]. The orexin gene or cDNA has also been characterized in non-mammalian species [8,23,34,43].

  • Influence of season and nutritional status on the direct effects of leptin, orexin-A, and ghrelin on luteinizing hormone and growth hormone secretion in the ovine pituitary explant model

    2014, Domestic Animal Endocrinology
    Citation Excerpt :

    The key regulatory agents include peptides with orexigenic properties such as ghrelin and orexin-A as well as peptides with anorexigenic properties (eg, leptin) that jointly “inform” the central nervous system about the current nutritional status [7–9]. Reduction in the pulsatile secretion of LH caused by nutritional restrictions can be reversed by leptin administration in sheep and cattle [10,11], and by orexin-A in female rats [12]. Leptin and ghrelin regulate GH secretion in both the negative and the positive energy balance states in sheep [10,13].

View all citing articles on Scopus
View full text