United States Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Roman L. Hruska U.S. Meat Animal Research Center: Reports
Accessibility Remediation
If you are unable to use this item in its current form due to accessibility barriers, you may request remediation through our remediation request form.
Date of this Version
2002
Document Type
Article
Citation
Published in Domestic Animal Endocrinology 23 (2002) 383–396.
Abstract
Granulocyte macrophage-colony stimulating factor (GM-CSF) increases ovine interferon-tau (oIFNτ) secretion by ovine conceptuses, but endometrial production of GM-CSF has not been characterized. Endometrial GM-CSF expression was evaluated in ovariectomized ewes implanted with estradiol-17β (E2) and/or progesterone (P4) for 14 days, in day 14 cyclic and day 14 pregnant ewes. Relative levels of endometrial GM-CSF mRNA were 3-fold higher in E2- and E2/P4-treated ewes than that of control or P4-treated ovariectomized ewes. Levels of endometrial GM-CSF mRNA for cyclic ewes were similar to E2- and E2/P4-treated ewes, but amounts of GM-CSF mRNA in pregnant ewes were 2-fold higher. GM-CSF concentrations in endometrial culture media, determined by GM-CSF bioassay, for cyclic and E2/P4-treated ovariectomized ewes were 3-fold higher than those of control, E2- and P4-treated ovariectomized ewes; however, amounts of GM-CSF in pregnant ewes were 2-fold higher. Immunoreactive GM-CSF, examined by western blot, was detected in the culture medium from E2/P4-treated ovariectomized, cyclic and pregnant ewes. Luminal and glandular epithelia and stromal regions were determined to be sites of GM-CSF expression by immunohistochemistry and in situ hybridization techniques. Data indicate that combined E2 and P4 treatment of ovariectomized ewes is sufficient to restore GM-CSF expression to the level found in cyclic ewes; however, GM-CSF mRNA and protein in pregnant ewes is 2-fold greater than in ovariectomized or cyclic ewes. These data suggest that the conceptus, in addition to steroids, may play a role in the regulation of endometrial production of GM-CSF.