Cortisol disrupts the ability of estradiol-17 beta to induce the LH surge in ovariectomized ewes
BN Pierce, IJ Clarke, AI Turner, ETA Rivalland, AJ Tilbrook
Domestic Animal Endocrinology | ELSEVIER SCIENCE INC | Published : 2009
Stress disrupts the preovulatory luteinizing hormone (LH) surge in females, but the mechanisms are unknown. We tested the hypothesis that cortisol compromises the ability of estrogen to induce a preovulatory-like LH surge in ovariectomized ewes in both the breeding and nonbreeding season. Luteinizing hormone surges were induced in ovariectomized ewes by treatment with progesterone followed by a surge-inducing estradiol-17beta (E2) stimulus using a crossover design. The experiment was replicated in the breeding and nonbreeding seasons. Cortisol reduced the incidence of LH surges irrespective of season. Cortisol increased the latency from E2 stimulus to the onset of the surge in the breeding s..View full abstract
Awarded by NIH
Awarded by EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH &HUMAN DEVELOPMENT
We thank Bruce Doughton, Adam Link, Lynda Morrish, and Jessica Thomas for their technical assistance. We also thank Dr. A. Parlow and the National Hormone and Peptide Program for LH assay reagents. We thank Dr. Fred J. Karsch for intellectual input to this work. This work was supported by NIH Grants HD30773, NIHT32-07048, NIH-T32-08322, and Monash University.