In vivo experiments were conducted to determine if elevated plasma glucocorticoid concentrations would suppress intrafollicular prostaglandin F2$ alpha$ (PGF2$ alpha$) synthesis and, thereby, inhibit ovulation in the pig. Following ACTH administration, PGF2$ alpha$ concentrations in FF tended to be lower than in controls. Injections of betamethasone partially suppressed the preovulatory rise of PGF2$ alpha$ in FF at 40h, although the effect was less marked than that produced by indomethacin. While no ovulations occurred in the indomethacin-treated group at any time, betamethasone resulted in a lower number of ovulated follicles at 44h than in the control animals. Progesterone concentrations were unaffected by the treatments. / In vitro studies were conducted with a spontaneously established cell line developed through continuous culturing of primary granulosa cells collected from prepuberal gilts six hours after they had received PMSG. Characterization of these cells revealed that aromatase and steroidogenesis were functional but gonadotropin receptors were not present. When extracellular PGF2$ alpha$ levels were measured, dexamethasone was able to significantly suppress PGF$ sb{2 alpha}$ concentrations, but not as effectively as with indomethacin. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.61233 |
| Date | January 1992 |
| Creators | Kwan, Ivy |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Animal Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001287587, proquestno: AAIMM74941, Theses scanned by UMI/ProQuest. |
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