出版社：American Society for Biochemistry and Molecular Biology
摘要：Little is known about the uptake or metabolism of essentialfatty acids (EFAs) in various mammalian organs. Thus, the distributionof deuterated -linolenic acid (18:3n-3) and linoleic acid (18:2n-6)and their metabolites was studied using a stable isotope tracertechnique. Rats were orally administered a single dose of amixture (20 mg each) of ethyl D5-18:3n-3 and D5-18:2n-6, and25 tissues per animal were analyzed for D5-labeled PUFAs at4, 8, 24, 96, 168, 240, 360, and 600 h after dosing. Plasma,stomach, and spleen contained the highest concentrations oflabeled precursors at the earliest time points, whereas otherinternal organs and red blood cells reached their maximal concentrationsat 8 h. The time-course data were consistent with liver metabolismof EFAs, but local metabolism in other tissues could not beruled out. Brain, spinal cord, heart, testis, and eye accumulateddocosahexaenoic acid with time, whereas skin accumulated mainly20:4n-6. On average, 16–18% of the D5-18:3n-3 and D5-18:2n-6initial dosage was eventually accumulated in tissues, principallyin adipose, skin, and muscle. Approximately 6.0% of D5-18:3n-3and 2.6% of D5-18:2n-6 were elongated/desaturated and stored,mainly in muscle, adipose, and the carcass. The remaining 78%of both precursors was apparently catabolized or excreted.Supplementary key words docosahexaenoic acid • arachidonic acid • polyunsaturated fatty acid • fatty acid metabolism • stable isotope • gas liquid chromatography-mass spectrometry • essential fatty acid
Abbreviations: BHT, butylated hydroxytoluene; Cmax, maximal concentration; Dmax, maximal amount; EFA, essential fatty acid; GC-MS, gas liquid chromatography-mass spectrometry; GI, gastrointestinal; PFB, pentafluorobenzyl; RBC, red blood cell
-linolenic acid (18:3n-3) and linoleic acid (18:2n-6) and their metabolites was studied using a stable isotope tracer technique. Rats were orally administered a single dose of a mixture (20 mg each) of ethyl D5-18:3n-3 and D5-18:2n-6, and 25 tissues per animal were analyzed for D5-labeled PUFAs at 4, 8, 24, 96, 168, 240, 360, and 600 h after dosing. Plasma, stomach, and spleen contained the highest concentrations of labeled precursors at the earliest time points, whereas other internal organs and red blood cells reached their maximal concentrations at 8 h. The time-course data were consistent with liver metabolism of EFAs, but local metabolism in other tissues could not be ruled out. Brain, spinal cord, heart, testis, and eye accumulated docosahexaenoic acid with time, whereas skin accumulated mainly 20:4n-6. On average, 
16–18% of the D5-18:3n-3 and D5-18:2n-6 initial dosage was eventually accumulated in tissues, principally in adipose, skin, and muscle. Approximately 6.0% of D5-18:3n-3 and 2.6% of D5-18:2n-6 were elongated/desaturated and stored, mainly in muscle, adipose, and the carcass. The remaining 78% of both precursors was apparently catabolized or excreted.
Supplementary key words docosahexaenoic acid • arachidonic acid • polyunsaturated fatty acid • fatty acid metabolism • stable isotope • gas liquid chromatography-mass spectrometry • essential fatty acid
Abbreviations: BHT, butylated hydroxytoluene; Cmax, maximal concentration; Dmax, maximal amount; EFA, essential fatty acid; GC-MS, gas liquid chromatography-mass spectrometry; GI, gastrointestinal; PFB, pentafluorobenzyl; RBC, red blood cell
