Translator Disclaimer
1 January 2006 Does Season Alter Responsiveness of the Reproductive Neuroendocrine Axis to the Suppressive Actions of Cortisol in Ovariectomized Ewes?
Author Affiliations +
Abstract

Season can profoundly influence activity of the hypothalamic-pituitary-adrenal axis and alter reproductive neuroendocrine responsiveness to stress and gonadal steroids. Here we tested the hypothesis that the inhibitory effect of a stress-like increment in plasma concentration of the adrenal steroid cortisol on pulsatile LH secretion varies with season. LH pulse patterns were monitored prior to and during the administration of cortisol in the same seven ovariectomized ewes during three stages of the yearly breeding cycle: breeding season, transition to anestrus, and midanestrus. The elevation in cortisol mimicked the rise in plasma level of cortisol in response to an immune/inflammatory stress. During all three seasons, cortisol acutely suppressed the pulsatile release of LH. This inhibition reflected a marked reduction of LH pulse amplitude and a minimal suppression of LH pulse frequency. Of interest, the suppressive effect of this physiologic increment in cortisol did not vary across seasons. This provides initial evidence that, in ovariectomized ewes, cortisol-induced suppression of pulsatile LH secretion differs from that of gonadal steroids in that it is not profoundly influenced by season.

Kellie M. Breen and Fred J. Karsch "Does Season Alter Responsiveness of the Reproductive Neuroendocrine Axis to the Suppressive Actions of Cortisol in Ovariectomized Ewes?," Biology of Reproduction 74(1), 41-45, (1 January 2006). https://doi.org/10.1095/biolreprod.105.045898
Received: 21 July 2005; Accepted: 1 September 2005; Published: 1 January 2006
JOURNAL ARTICLE
5 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top