Metabolites of arachidonic acid, known as eicosanoids, result from two enzymatic pathways: cyclooxygenase (COX) and lipoxygenase (LOX). Indomethacin (INDO), at a dose level of approximately 10 mg/kg, has been commonly used in studies on the role of prostagiandins (PG) in the porcine ovulatory process since it was believed to be specific in its inhibition of the COX pathway. Other evidence suggests that INDO also has inhibitory effects on the formation of LOX metabolites including 12- and 15-hydroxyeicosatetraenoic acid (HETE). There is also evidence that LOX metabolites may have a role in the ovulatory process of the rat and the pig. In the previous studies on PGs in porcine ovulation, the effect of INDO on LOX metabolites was not examined. It has been shown that progesterone has a role in the formation of eicosanoids in the ovary in the rat and the ewe. The results of this study indicate that an intramuscular injection of INDO, at dose levels as high as 5 mg/kg, reduces ovulation rat and preovulatory follicular fluid concentrations of PGF2alpha without affecting concentrations of 12- and 15-HETE in the gonadotropin-primed pig. Indomethacin, at dose levels as low as 1 mg/kg, reduced ovulation rate and intrafollicular PGF2alpha concentrations but 0.1 mg/kg had no effect on ovulation rate or PGF2alpha. In cultured granulosa and theca interna cells, 10 ng or greater of INDO per 3 x 105 cells reduces PGF2alpha accumulation in the media. Accumulation of 12- and 15-BETE in the media was reduced by 100 ng or greater of INDO per 3 x 10 5 cells. To examine the role of progesterone in the formation of eicosanoids, danazol, an inhibitor of steroidogenesis, was added to cultures of porcine follicular cells. This treatment had no effect on progesterone production by either cell type and, similarly, had no effect on eicosanoid production. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20248 |
| Date | January 1997 |
| Creators | Cassidy, Carrie. |
| Contributors | Downey, B. R. (advisor) |
| 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: 001609489, proquestno: MQ44139, Theses scanned by UMI/ProQuest. |
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