膳食脂肪酸构成对小鼠淋巴细胞功能和脂质过氧化的影响

目的:探讨膳食多不饱和脂肪酸n-6/n-3比值对小鼠T淋巴细胞功能和脂质过氧化的影响。方法:96只BALb/c小鼠随机分为8组:饱和脂肪酸:单不饱和脂肪酸:多不饱和脂肪酸(S∶M∶P)为1:1.5:3.7和1:1.5:1,n-6/n-3比值分别为1、7.5、15、30,各4组。基础饲料采用AIN-93G配方,各组饲料的脂肪酸构成以食用油脂调配。饲养12w。测定小鼠T淋巴细胞功能,IL-2和血清丙二醛(MDA)水平。结果:S:M:P为1:1.5∶3.7,n-6/n-3为1时,小鼠T淋巴细胞增殖活性、IL-2水平均显著降低(P<0.05),且两者显著正相关(r=0.438,P<0.05),n-6/n-3为1、30时,血清MDA水平明显高于n-6/n-3为7.5和15组(P<0.05);S:M:P为1:1.5:1,n-6/n-3为1时,小鼠T淋巴细胞增殖活性、CD4+/CD8+T细胞比例、IL-2水平明显降低(P<0.05),n-6/n-3为1、30时,血清MDA水平明显高于n-6/n-3为7.5组(P<0.05)。结论:S:M:P为1:1.5:3.7和1:1.5:1,n-6/n-3为1时,T淋巴细胞功能受到抑制,其作用机制可能与IL-2有关;DHA对CD4+/CD8+T细胞比例的抑制作用可能大于ALA;结合脂质过氧化程度来考虑,膳食n-6/n-3为7.5～15范围内较为理想。

EFFECTS OF DIFFERENT DIETARY FATTY ACID COMPOSITION ON T LYMPHOCYTE FUNCTIONS AND LIPID PEROXIDATION IN MICE

Objective: To study the effects of dietary n-6/n-3 PUFA ratio on T lymphocyte functions in mice. Methods: 96 male BALb/c mice were randomly divided into 8 groups with dietary S:M:P 1:1.5:3.7 or 1:1.5:1, respectively. The n-6/n-3 PUFA ratio was 1, 7.5, 15, 30 respectively in each S:M:P diet. Each diet contained 70.0g/kg lipid,and different n-6/n-3 PUFA ratios by mixing different oils. At the end of 12w, all mice were killed and blood was collected. The spleen T lymphocyte proliferation, IL-2 production and serum MDA were measured. Results: When dietary S:M:P was 1:1.5:3.7, the proliferation of spleen lymphocytes and IL-2 production from mice with dietary n-6/n-3 ratio 1 were suppressed (P<0.05). IL-2 production was significantly correlated with the proliferation of spleen lymphocytes(r=0.438, P<0.05). The serum MDA of groups with n-6/n-3 ratio 1 and 30 were higher than that of groups with n-6/n-3 ratio 7.5 and 15 (P<0.05). When dietary S:M:P was 1:1.5:1, the proliferation of spleen lymphocytes, CD4 , CD8 T lymphocyte and IL-2 production from mice with dietary n-6/n-3 ratio 1 were decreased (P<0.05). The serum MDA of groups with n-6/n-3 ratio 1 and 30 were higher than that of group with n-6/n-3 ratio 7.5 (P<0.05). Conclusions: The T lymphocyte function in mice was suppressed when dietary n-6/n-3 ratio approximated 1,was relatively moderate while dietary n-6/n-3 ratio ranged from 7.5 to 15, in which the serum MDA was relatively lower.