Kiyose C, Muramatsu R, Kameyama Y, Ueda T, Igarashi O
Institute of Environmental Science for Human Life, Ochanomizu University, Tokyo, Japan.
Am J Clin Nutr. 1997 Mar;65(3):785-9. doi: 10.1093/ajcn/65.3.785.
We investigated changes in the concentrations of the stereoisomers of alpha-tocopherol in serum and lipoproteins in seven normal, healthy women aged 21-37 y who had received oral administration of natural and synthetic alpha-tocopheryl acetate. This study was conducted in three separate periods of 28 d each; there was a 3-mo washout period between each experimental period. During the first period the subjects were administered a daily dose of 100 mg RRR-alpha-tocopherol/d, whereas in the second and third periods 100 mg all-rac-alpha-tocopheryl acetate/d and 300 mg all-rac-alpha-tocopheryl acetate/d were given, respectively. Blood samples were collected 3 d before each treatment and 1, 3, 7, 14, and 28 d after treatment. alpha-Tocopherol stereoisomer concentrations in serum and lipoproteins (very-low-, low-, and high-density lipoproteins) were determined by the chiral HPLC method. The bioavailability of RRR-alpha-tocopherol was greater than that of all-rac-alpha-tocopheryl acetate. When bioavailability was estimated from the increase in the concentration of RRR- or all-rac-alpha-tocopherol in serum, bioavailability of RRR-alpha-tocopherol administered at 100 mg/d was not different from that of all-rac-alpha-tocopheryl acetate administered at 300 mg/d. 2R-Isomers and small amounts of 2S-isomers were detected in the serum lipoproteins of subjects administered all-rac-alpha-tocopheryl acetate.
我们研究了7名年龄在21 - 37岁的正常健康女性在口服天然和合成α-生育酚醋酸酯后，血清和脂蛋白中α-生育酚立体异构体浓度的变化。本研究分三个独立阶段进行，每个阶段为期28天；每个实验阶段之间有3个月的洗脱期。在第一阶段，受试者每天服用100 mg RRR-α-生育酚；而在第二和第三阶段，分别给予100 mg消旋-α-生育酚醋酸酯/天和300 mg消旋-α-生育酚醋酸酯/天。在每次治疗前3天以及治疗后1、3、7、14和28天采集血样。采用手性高效液相色谱法测定血清和脂蛋白（极低密度、低密度和高密度脂蛋白）中的α-生育酚立体异构体浓度。RRR-α-生育酚的生物利用度高于消旋-α-生育酚醋酸酯。当根据血清中RRR-或消旋-α-生育酚浓度的增加来估计生物利用度时，每天服用100 mg的RRR-α-生育酚的生物利用度与每天服用300 mg的消旋-α-生育酚醋酸酯的生物利用度没有差异。在服用消旋-α-生育酚醋酸酯的受试者的血清脂蛋白中检测到了2R-异构体和少量的2S-异构体。
