To determine the possible roles of tumor necrosis factor-α (TNFα) and nitric oxide (NO) in the bovine oviduct, ampulla and isthmus collected during the estrous cycle were exposed for 18 h to TNFα, NO donor (NONOate), NO synthase inhibitors (L-NOARG, L-NAME and AMT) and oxytocin (OT) as a positive control. Prostaglandins (PGs) and NO2/NO3 in conditioned media were measured. TNFα stimulated PGF2α secretion on Day 0 (onset of estrus = Day 0) and Days 2-3, in both the ampulla and isthmus, but on Days 18-20 only in ampulla. TNFα increased PGE 2 secretion in both fragments in each phase. NONOate did not affect PGF2α secretion on Days 18-20, whereas this NO donor stimulated PGF2α secretion in both fragments on Day 0 and Days 2-3. TNFα increased NO2/NO3 production in every examined phase in the ampulla and on Days 2-3 in the isthmus. L-NAME lowered NO 2/NO3 production regardless of phase or fragment. L-NOARG and AMT lowered NO2/NO3 production in both fragments on Day 0 and Days 2-3. The possible role of TNFα, NO or PGs on the oviductal contractility during the early-luteal phase was also examined. Neither TNFα nor NONOate influenced contractility in either fragment. Although PGF2α stimulated the contraction in both fragments, PGE 2 decreased it. When taken together, TNFα seems to play some role as a modulator of PGF2α and PGE2 production and for transferring the embryo from the oviduct to the uterus by stimulating NO production in the bovine oviduct.
- Nitric oxide
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)