Toutain P L, Laurentie M P, Hidiroglou N, Hidiroglou M
Ecole Nationale Vétérinaire de Toulouse, Départment de Physiopathologie, France.
Ann Rech Vet. 1992;23(2):117-30.
The disposition of radiotocopherol after intraperitoneal administration of 14C-labelled-DL-alpha-tocopherol (1 microCi/kg bw, dose 1) and 3H-labelled-DL-alpha-tocopherol (4 microCi/kg bw dose 4) and of D-alpha-tocopherol, after intraperitoneal administration of DL-alpha-tocopherol acetate (100 mg/kg bw) was investigated in sheep. Plasma samples were taken at regular intervals after dosing and assayed for radioactivity and D-alpha-tocopherol. Plasma profiles were modelized using a compartmental approach and the input entry rate (for radioactivity) was identified using a numerical deconvolution method. Based on plasma specific activity (dose 1 and dose 4) and D-alpha-tocopherol plasma concentration (unlabelled alpha-tocopherol acetate), half-lives were not significantly different (99.6 +/- 28.3 h, 121.3 +/- 38.5 h and 75.0 +/- 49.75 h after dose 1, dose 4 and unlabelled alpha-tocopherol respectively). The times to reach maximal plasma concentrations were similar for the 3 test articles (mean values ranging from 21.5 to 26.7 h). The only significant difference was observed for the apparent volume of distribution (with respect to bioavailability) which was much larger for the unlabelled test article. Deconvolution study of plasma specific activity showed: i), that the maximal input rate was reached only after a short delay (3 to 12 h); ii), that half of the activity was absorbed after a delay of 38.13 +/- 16.76 h (dose 1) and 44.3 +/- 6.50 h (dose 4); and iii), that 90% of the activity was absorbed after 151.2 +/- 27.3 h (dose 1) and 162.3 +/- 11.2 (dose 4). It is concluded that the intraperitoneal route is of interest for alpha-tocopherol administration, but that more information is required to determine the exact process of absorption.
在绵羊体内研究了腹腔注射14C标记的DL-α-生育酚（1微居里/千克体重，剂量1）和3H标记的DL-α-生育酚（4微居里/千克体重，剂量4）以及腹腔注射DL-α-生育酚醋酸酯（100毫克/千克体重）后D-α-生育酚的处置情况。给药后定期采集血浆样本，检测放射性和D-α-生育酚。使用房室模型方法对血浆曲线进行建模，并使用数值反卷积方法确定输入进入速率（针对放射性）。根据血浆比活性（剂量1和剂量4）和D-α-生育酚血浆浓度（未标记的α-生育酚醋酸酯），半衰期无显著差异（剂量1、剂量4和未标记的α-生育酚给药后分别为99.6±28.3小时、121.3±38.5小时和75.0±49.75小时）。三种受试品达到最大血浆浓度的时间相似（平均值在21.5至26.7小时之间）。观察到的唯一显著差异是分布表观体积（相对于生物利用度），未标记的受试品要大得多。血浆比活性的反卷积研究表明：i），最大输入速率仅在短暂延迟（3至12小时）后达到；ii），一半的活性在38.13±16.76小时（剂量1）和44.3±6.50小时（剂量4）的延迟后被吸收；iii），90%的活性在151.2±27.3小时（剂量1）和162.3±11.2（剂量4）后被吸收。结论是，腹腔途径对于α-生育酚给药具有意义，但需要更多信息来确定确切的吸收过程。
