The purpose of this study was to investigate which type(s) of somatic cells release nitric oxide (NO) in response to Escherichia coli lipopolysaccharide (LPS) and cytokines in vitro and how NO affects superoxide anion (O2-) production by bovine neutrophils and blood monocytes. Mammary epithelial cell line (FbE) released NO after stimulation with recombinant bovine interleukin-1beta (rBoIL-1beta). Moreover, monocytes produced NO in response to recombinant bovine interferon gamma (rBoIFN-gamma) alone or in combination with LPS in a dose- and time-dependent manner. Nitric oxide production was diminished by addition of inducible nitric oxide synthase (iNOS) inhibitors L-N 6-(1-Iminiethyl)lysine or aminoguanidine. However, NO release could not be induced in freshly isolated bovine neutrophils under the experimental conditions used, even after 96 h of incubation. Interestingly, when reverse transcriptase polymerase chain reaction (RT-PCR) with specific primers for iNOS was performed to study mRNA expression, iNOS expression was observed in both monocytes and neutrophils in response to LPS and rBoIFN-gamma. / Unlike neutrophils, monocytes were poor producers of superoxide anion under the experimental conditions. A neutrophil-monocyte co-culture system was set up to study the effect of monocyte derived-NO and iNOS inhibitors on superoxide anion production by neutrophils. Neither NO derived from activated monocytes nor iNOS inhibitors seemed to have an effect on bovine neutrophil ability to release O2-. These results suggest that mammary epithelial cells and mononuclear phagocytes are among the cell types responsible for the important quantities of NO released by somatic cells recovered from LPS-infused mammary quarters during endotoxin-induced bovine mastitis. In addition, NO or iNOS inhibitors have no effect on the ability of activated bovine neutrophils to produce superoxide anions.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.30348 |
| Date | January 2000 |
| Creators | Boulanger, Véronique. |
| Contributors | Zhao, Xin (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: 001764878, proquestno: MQ64324, Theses scanned by UMI/ProQuest. |
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