Wang X D, Marini R P, Hebuterne X, Fox J G, Krinsky N I, Russell R M
Gastrointestinal Nutrition Laboratory, U.S. Department of Agriculture Human Nutrition Research Center, Boston, Massachusetts.
Gastroenterology. 1995 Mar;108(3):719-26. doi: 10.1016/0016-5085(95)90444-1.
BACKGROUND/AIMS: beta-Carotene and alpha-tocopherol may have either antagonistic or synergistic effects on each other's absorption and metabolism. The effects of both physiological and pharmacological concentrations of alpha-tocopherol on the absorption and metabolism of beta-carotene in ferret intestine were determined.
A high concentration of beta-carotene was perfused through the upper portion of the small intestine of ferrets in vivo with varying levels of alpha-tocopherol. The effluent of a mesenteric lymph duct cannulation, the intestinal mucosal scraping, and portal vein blood were sampled and analyzed by high-performance liquid chromatography.
The lymphatic transport of beta-carotene was enhanced 4-fold by alpha-tocopherol at a physiological dose and 12-21-fold at a pharmacological dose. The lymphatic transport of alpha-tocopherol was linearly (r = 0.8; P < 0.05) related to the luminal alpha-tocopherol concentration even in the presence of a high concentration of beta-carotene. Furthermore, alpha-tocopherol increased the conversion of beta-carotene into retinol in the intestine in a dose-dependent manner.
alpha-Tocopherol has a positive effect on the intestinal absorption of intact beta-carotene and may modulate the metabolic conversion of beta-carotene into retinoids.
背景/目的：β-胡萝卜素和α-生育酚可能对彼此的吸收和代谢具有拮抗或协同作用。测定了生理浓度和药理浓度的α-生育酚对雪貂肠道中β-胡萝卜素吸收和代谢的影响。
在体内将高浓度的β-胡萝卜素灌注到雪貂小肠上部，并加入不同水平的α-生育酚。对肠系膜淋巴管插管的流出液、肠黏膜刮片和门静脉血进行采样，并通过高效液相色谱法进行分析。
生理剂量的α-生育酚使β-胡萝卜素的淋巴转运增强4倍，药理剂量下增强12 - 21倍。即使在存在高浓度β-胡萝卜素的情况下，α-生育酚的淋巴转运与肠腔α-生育酚浓度呈线性相关（r = 0.8；P < 0.05）。此外，α-生育酚以剂量依赖的方式增加了肠道中β-胡萝卜素向视黄醇的转化。
α-生育酚对完整β-胡萝卜素的肠道吸收具有积极作用，并可能调节β-胡萝卜素向类视黄醇的代谢转化。
