Abstract
To determine the physiological significance of tumor necrosis factor-α (TNFα) in the regulation of endometrial prostaglandin (PG) release in cattle, we investigated the effects of TNFα on the secretion of PGE2 and PGF2α by bovine endometrium during the estrous cycle. Bovine uteri were classified into six stages (estrus: Day 0, early luteal I: Days 2 to 3, early luteal II: Days 5 to 6, mid-luteal: Days 8 to 12, late luteal: Days 15 to 17 and follicular: Days 19 to 21). After 1 h of pre-incubation, endometrial tissues (20 to 30 mg) were exposed to 0 or 0.6 nM TNFα for 4 h. The PGE2 concentrations in the medium were higher in the luteal stages than in the follicular stage and in estrus. In contrast, PGF2α concentrations were higher in the follicular stage and in estrus than in the luteal stages. The ratio of the basal concentrations of PGE2 and PGF2α (PGE2/PGF2α ratio) was higher in the luteal stages than in the follicular stage and in estrus. Although TNFα stimulated both PGE2 and PGF2α secretion during the entire period of the estrous cycle, the level of stimulation of TNFα on PGE2 output by the bovine endometrium does not show the same cyclical changes as that shown on PGF2α output. The stimulation of TNFα resulted in a decrease in the PGE2/PGF2α ratio only in the late luteal stage. Furthermore, TNFα stimulated PGE2 secretion in stromal, but not epithelial cells. The overall results suggest that TNFα is a potent regulator of endometrial PGE2 secretion as well as PGF2α secretion during the entire period of estrous cycle, and that TNFα plays different roles in the regulation of secretory function of bovine endometrium at different phases of the estrous cycle.
Original language | English |
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Pages (from-to) | 1667-1678 |
Number of pages | 12 |
Journal | Theriogenology |
Volume | 55 |
Issue number | 8 |
DOIs | |
Publication status | Published - May 1 2001 |
Keywords
- Cattle
- Endometrium
- Prostaglandin E
- Prostaglandin F
- Tumor necrosis factor-α
ASJC Scopus subject areas
- Small Animals
- Food Animals
- Animal Science and Zoology
- Equine