Dietary fat effect on canine neutrophil membrance fatty acid composition and cell functions /
The effects of diets rich in saturated fatty acids, n-6 PUFA, 18 n-3 fatty acids, or 20/22-carbon n-3 fatty acids on canine neutrophil membrane fatty acid composition, phagocytosis, membrane fluidity, superoxide and leukotriene (LTB) production were investigated. Four groups of 10 dogs, 10 per group...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731686031&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The effects of diets rich in saturated fatty acids, n-6 PUFA, 18 n-3 fatty acids, or 20/22-carbon n-3 fatty acids on canine neutrophil membrane fatty acid composition, phagocytosis, membrane fluidity, superoxide and leukotriene (LTB) production were investigated. Four groups of 10 dogs, 10 per group, were fed a low fat basal diet supplemented with either safflower oil (SFO), beef tallow (BT), linseed oil (LSO), or Menhaden fish oil (MHO) for 28 days. Dietary fat provided 40.8 % of calories and the n-6:n-3 ratios of the diets were 101, 9.7, 0.38, and 0.34 for the SFO, BT, LSO and MHO groups, respectively. The MHO group had significantly less LTB₄ and significantly greater LTB₅ than the other 3 groups. The LSO group had significantly greater LTB₅ production than the SFO and BT groups. The LSO and MHO groups had significantly less superoxide production when compared to the SFO and BT groups. The MHO group had significantly greater incorporation of n-3 fatty acids (20:5, 22:5, and 22:6) into membrane lipids. The LSO group also had significant incorporation of 20:5n-3, 22:5n-3, but to a lesser degree, than the SFO and BTO groups. Interestingly, no 22:6n-3 was observed in the membrane lipids. Membrane fluidity was determined using fluorescence polarization and phagocytosis was determined using flow cytometry. Membrane fluidity and phagocytosis were linearly correlated. The MHO and LSO groups had significantly greater membrane fluidity compared to the SFO and BT groups, and the SFO had significantly greater membrane fluidity compared to the BT group. No differences among groups in the number of cells that ingested 1 or 2 beads were observed. The LSO and MHO groups had significantly greater uptake of 3, 4, and > 4 beads compared to the SFO and BTO groups. The MHO and LSO groups also had a significantly greater number of cells that participated in phagocytosis compared to the SFO and BT groups. The findings from this study clearly show that dietary n-3 fatty acids increase membrane fluidity and improve phagocytosis. Additionally, dietary 18- or 20/22-carbon n-3 fatty acids are differentially incorporated into neutrophil membranes and differentially affect cell functions even when fed at the same n-6:n-3 fatty acid ratio. Thus, when formulating diets to modify inflammation, both the type and amounts of n-3 fatty acids and not simply the total n-6 to total n-3 fatty acid ratio must be considered. |
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| Item Description: | Vita. "Major Subject: Nutrition". |
| Physical Description: | x, 170 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 138-156). |