饮食脂肪对小鼠脑聚集长链多不饱和脂肪酸的影响

目的探讨高脂饮食状态下不同脂肪酸种类对脑聚集二十二碳六烯酸(DHA)和花生四烯酸(AA)的影响。方法采用C57BL/6J雌性小鼠,在成年期和幼年期分别给予不同种类高脂饲料(18%脂肪,供能比为36%)喂养,分为高脂豆油饲料、高脂鱼油饲料和高脂豆油∶鱼油(5∶1)混合饲料组,以正常饲料(6%脂肪来自豆油,供能比为12%)为对照,时间为4个月。然后采用气相色谱法对小鼠脑组织脂肪酸进行测定。结果4组不同饲料对脑组织中DHA和AA水平的影响在成年期和幼年期小鼠之间无差异。与高脂豆油饲料组相比,高脂鱼油饲料组小鼠脑组织中DHA的含量无显著变化,但AA及其前体亚油酸(LA)含量均显著降低,导致DHA/AA比值升高;高脂豆油∶鱼油混合饲料组小鼠脑组织中DHA、AA及其前体LA含量均无显著变化,但DHA/AA比值升高。结论饮食中鱼油n-3脂肪的摄入增加不影响脑DHA水平,但减少了AA的聚集,使得DHA/AA比值升高。

Effects of Dietary n-3 and n-6 Triglycerides on Long Chain Polyunsaturated Fatty Acid Accretion in Mouse Brain

Objective In this study the effects of dietary n-3 and n-6 fatty acids on brain accretion of docosahexaenoic acid(DHA) and arachidonic acids(AA) were investigated.Methods C57BL/6J female adult mice were fed three different high-fat(18% fat by weight supplying 36% of total energy) diets: soy oil,fish oil and soy:fish oil(5:1) respectively with normal chow diet(6% of fat as soy oil supplying 12% of total energy) as control,for a period of 4 months.Also some mice were mated for breeding new mice with high-fat diets being started 1 month before mating and ended at 2 months following mouse birth.Brain fatty acids were analyzed by gas chromatography and expressed as percent(%) of total fatty acids.Results No differences were found in the effects of dietary fat on DHA and AA levels in brain between young mice and adult mice.Compared to soy oil-fed mice,AA accretion in brain was decreased with no changes in DHA accretion leading to increased DHA/AA ratio in fish oil-fed mice,whereas no changes in both DHA and AA accretion were found but DHA/AA ratio was increased in soy:fish oil-fed mice.Conclusion Increased intake of fish oil n-3 triglycerides does not enhance DHA accretion but increases DHA/AA ratio in mouse brain.