The effect of eicosapentaenoic acid on rat lymphocyte proliferation depends upon its position in dietary triacylglycerols

S. Kew, S. Wells, Frank Thies, G. P. McNeill, G. T. Quinlan, G. T. Clark, H. Dombrowsky, A. D. Postle, P. C. Calder

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Animal and human studies have shown that greatly increasing the amount of fish oil [rich in long-chain (n-3) PUFA] in the diet can decrease lymphocyte functions. The effects of a more modest provision of long-chain (n-3) PUFA and whether eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6) have the same effects as one another are unclear. Whether the position of 20:5 or 22:6 in dietary triacylglycerols (TAG) influences their incorporation into immune cells and their subsequent functional effects is not known. In this study, male weanling rats were fed for 6 wk one of 9 diets that contained 178 g lipid/kg and that differed in the type of (n-3) PUFA and in the position of these in dietary TAG. The control diet contained 4.4 g alpha-linolenic acid (18:3)/100 g total fatty acids. In the other diets, 20:5 or 22:6 replaced a portion (50 or 100%) of 18:3, and were in the sn-2 or the sn-1(3) position of dietary TAG. There were significant dose-dependent increases in the proportion of 20:5 or 22:6 in spleen mononuclear cell phospholipids when 20:5 or 22:6 was fed. These increases were at the expense of arachidonic acid and were largely independent of the position of 20:5 or 22:6 in dietary TAG. Spleen lymphocyte proliferation increased dose dependently when 20:5 was fed in the sn-1 (3) position of dietary TAG. There were no significant differences in interleukin-2, interferon-gamma or interleukin-10 production among spleen cells from rats fed the different diets. Prostaglandin E-2 production by spleen mononuclear cells was decreased by inclusion of either 20:5 or 22:6 in the diet in the sn-1(3) position. Thus, incorporation of 20:5 or 22:6 into spleen mononuclear cell phospholipids is not influenced by the position in dietary TAG. However, the pattern of incorporation may be influenced, and there are some differential functional effects of the position of long-chain (n-3) PUFA in dietary TAG. A moderate increase in the intake of 20:5 at the sn-1 (3) position of dietary TAG increases lymphocyte proliferation.

Original languageEnglish
Pages (from-to)4230-4238
Number of pages8
JournalThe Journal of Nutrition
Volume133
Publication statusPublished - 2003

Keywords

  • eicosapentaenoic acid
  • docosahexaenoic acid
  • structured triacylglycerol
  • lymphocyte
  • rats
  • POLYUNSATURATED FATTY-ACIDS
  • MONONUCLEAR CELL-PROLIFERATION
  • MURINE PERITONEAL-MACROPHAGES
  • INTERFERON-GAMMA PRODUCTION
  • PROTEIN-KINASE-C
  • FISH-OIL
  • DOCOSAHEXAENOIC ACID
  • PHOSPHOLIPASE-D
  • INTERLEUKIN-2 PRODUCTION
  • CYTOKINE PRODUCTION

Cite this

Kew, S., Wells, S., Thies, F., McNeill, G. P., Quinlan, G. T., Clark, G. T., Dombrowsky, H., Postle, A. D., & Calder, P. C. (2003). The effect of eicosapentaenoic acid on rat lymphocyte proliferation depends upon its position in dietary triacylglycerols. The Journal of Nutrition, 133, 4230-4238.