[Effect of dietary n-6/n-3 polyunsaturated fatty acid ratio on spleen lymphocyte's function and fatty acid composition in mice].

Objective: To study the effect of dietary n-6/n-3 PUFA ratio on spleen lymphocyte's function and fatty acid composition in mice.
Methods: Male BALb/c mice were divided into 5 groups: the dietary S : m : p was 1 : 1.5 : 1 n-6/ n-3 PUFA ratio was 1, 7.5, 15, 30 respectively, and in the control group, dietary S : M : P was 1 : 1.5 : 3.7, which was followed the AIN-93G formulation. All groups consumed purified diet based on the AIN-93G formulation. The different n-6/ n-3 PUFA ratios in diets were varied by mixing of oils. After 12 wks breeding, all mice were sacrificed, and the function and fatty acid composition of Lymphocyte, IL-2 and PGE2 concentration were measured.
Results: When dietary n-6/n-3 PUFA ratio approximated 1, the lymphocyte proliferation, proportions of CD4+ and CD8+ T cell, IL-2 and PGE2 concentration decreased significantly. The concentration of C18 : 2, C20 : 4, n-6 PUFA in lymphocyte decreased significantly; Meanwhile, the concentration of C22 : 6, C16 : 1, C18 : 1 and total MUFA in lymphocyte significantly higher than other groups. The concentration of C2 : 6 in lymphocytes were significantly negative correlated with the proliferation of spleen lymphocytes. The concentration of C20 : 5 in lymphocyte was significantly negative correlated with the proportions of CD4+ T cell and IL-2 level. The concentration of C16 : 1 in lymphocyte was significantly negative correlated with the proportions of CD4+ and CD8+ T cell.
Conclusion: The fatty acid composition of diet affected that of lymphocyte in mice. Compared with the T lymphocyte function in diet with n-6/n-3 ratio approximated 30, the T lymphocyte function in mice was suppressed when dietary n-6/n-3 ratio approximated 1.