Yeh Y Y, Yeh S M, Lien E L
Department of Nutrition, The Pennsylvania State University, University Park 16802, USA.
Lipids. 1998 May;33(5):513-20. doi: 10.1007/s11745-998-0235-5.
Artificially reared infant rats were used to determine the effects of long-chain polyunsaturated fatty acid (LCPUFA) supplementation on blood and tissue concentrations of arachidonic acid (AA) and docosahexaenoic acid (DHA). Beginning at 7 d of age, infant rats were fed for 10 d with rat milk formulas supplemented with AA at 0, 0.5 and 1.0%, or supplemented with DHA at 0, 0.5 and 1.0% of total fatty acid. The supplementation of AA increased accretion of the fatty acid in tissue and blood phospholipids with a maximum increase of 9% in brain, 15% in liver, 25% in erythrocytes, and 43% in plasma above the values of unsupplemented infant rats. Rat milk formula containing 1.0% of AA had no added benefits over that containing 0.5% of AA. The supplementation of DHA increased phospholipid DHA by a maximum of 24% in brain, 87% in liver, 54% in erythrocytes, and 360% in plasma above the unsupplemented control. The increase in tissue and blood DHA was concentration-dependent on formula fatty acid. Brain phosphatidylcholine and phosphatidylethanolamine were similarly enriched with AA and DHA by supplementation of the corresponding fatty acids. In general the observed increase of AA was accompanied by a decrease in 16:0, 18:1 n-9, and/or 18:2n-6, whereas the increased DHA was associated with a reduction of 18:1n-9, 18:2n-6, and/or 20:4n-6. Clearly, infant rats were more responsive to DHA than AA supplementation, suggesting a great potential of dietary manipulation to alter tissue DHA concentrations. However, the supplementation of DHA significantly decreased tissue and blood AA/DHA ratios (wt%/wt%), whereas there was little or no change in the ratio by AA supplementation. Although the physiological implications of the levels of AA and DHA, and AA/DHA ratios achieved under the present experimental conditions are not readily known, the findings suggest that artificial rearing could provide a suitable model to investigate LCPUFA requirements using various sources of AA and DHA in rats.
使用人工饲养的幼鼠来确定补充长链多不饱和脂肪酸（LCPUFA）对花生四烯酸（AA）和二十二碳六烯酸（DHA）的血液及组织浓度的影响。从7日龄开始，给幼鼠喂食10天添加了占总脂肪酸0%、0.5%和1.0%的AA或添加了占总脂肪酸0%、0.5%和1.0%的DHA的大鼠奶粉。补充AA增加了组织和血液磷脂中该脂肪酸的蓄积，与未补充的幼鼠相比，大脑中增加最多达9%，肝脏中增加15%，红细胞中增加25%，血浆中增加43%。含1.0% AA的大鼠奶粉相比含0.5% AA的大鼠奶粉并无额外益处。补充DHA使大脑中磷脂DHA最多增加24%，肝脏中增加87%，红细胞中增加54%，血浆中增加360%，高于未补充的对照组。组织和血液中DHA的增加与配方奶粉脂肪酸浓度呈正相关。通过补充相应脂肪酸，大脑磷脂酰胆碱和磷脂酰乙醇胺中AA和DHA同样得到富集。总体而言，观察到的AA增加伴随着16:0、18:1 n-9和/或18:2n-6的减少，而DHA增加与18:1n-9、18:2n-6和/或20:4n-6的减少相关。显然，幼鼠对DHA补充的反应比对AA补充的反应更明显，这表明饮食调控在改变组织DHA浓度方面具有巨大潜力。然而，补充DHA显著降低了组织和血液中的AA/DHA比值（重量百分比/重量百分比），而补充AA时该比值几乎没有变化。尽管在当前实验条件下达到特定水平的AA、DHA及AA/DHA比值的生理意义尚不清楚，但这些发现表明人工饲养可为使用大鼠中AA和DHA的各种来源研究LCPUFA需求提供合适的模型。
