Fish oil alters T-lymphocyte proliferation and macrophage responses in Walker 256 tumor-bearing rats
Fish oil alters T-lymphocyte proliferation and macrophage responses in Walker 256 tumor-bearing rats
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DOI：
10.1016/j.nut.2005.11.001
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发表时间：
2006-04-01
期刊：
影响因子：
4.4
通讯作者：
Fernandes, LC
中科院分区：
文献类型：
--
作者：
Pizato, N;Bonatto, S;Fernandes, LC
Objective: We investigated the effect of the dietary ratio of omega-6 to omega-3 polyunsaturated fatty acids (PUFAs) from postweaning until adulthood on T-lymphocyte proliferation, T-lymphocyte subpopulations (helper and cytotoxic), and production of cytotoxic mediators by macrophages in tumor-bearing rodents.Methods: Weanling male Wistar rats received a normal low-fat (40 g/kg of diet) chow diet or a high-fat (300 g/kg) diet that included fish or sunflower oil or blends of fish and sunflower oils to yield omega-6:omega-3 PUFA ratios of approximately 6:1, 30:1, and 60:1 ad libitum. After 8 wk, 50% of rats in each group were inoculated with 1 mL of 2 X 10(7) Walker 256 cells. Fourteen days after tumor inoculation, animals were killed and lymphocytes and macrophages were obtained for study.Results: The diets richest in w-6 PUFA resulted in higher proliferation of thymus, spleen, and gut-associated lymphocytes compared with the chow diet irrespective of tumor burden. In contrast, the fish oil diet resulted in lower proliferation of thymus and spleen lymphocytes compared with the chow diet. Diets rich in omega-6 PUFA decreased the proportion of CD8(+) lymphocytes. In non-tumor-bearing and tumor-bearing rats, hydrogen peroxide production by macrophages was highest in rats that consumed diets high in omega-3 PUFAs. Superoxide and nitric oxide production were little affected by the dietary ratio of omega-6 to omega-3 PUFAs.Conclusion: Dietary omega-6 and omega-3 PUFA contents alter immune function in non-tumor-bearing and tumor-bearing rats. The omega-3 PUFAs decreased T-cell proliferation but increased hydrogen peroxide production compared with omega-6 PUFAs. Decreased tumor growth and cachexia and increased survival previously reported for fish oil in Walker 256 tumor-bearing rats may be related to improved macrophage function rather than to improved T-cell function. (c) 2006 Elsevier Inc. All rights reserved.
