Sundaresan P Ramnathan, Marmillot Phillipe, Liu Quing-Hong, Mitchell Geraldine V, Grundel Erich, Lakshman M Raj
Division of Research and Applied Technology, Office of Nutritional Products, Labeling and Dietary Supplements, Center for Food Safety & Applied Nutrition, Food and Drug Administration, Washington, DC 20204, USA.
Int J Vitam Nutr Res. 2005 Mar;75(2):133-41. doi: 10.1024/0300-9831.75.2.133.
Dietary factors affecting tissue storage of beta-carotene (BC), alpha-tocopherol (alpha-T), and retinol (ROL) in mammals include taurocholate, protein, and fat. Few studies have examined the effects of these factors on the storage of BC, retinyl esters, and alpha-T in a mammalian system that is similar to humans. The main objective of the study was to investigate the effects of taurocholate (TC), fat, and protein on the absorption and metabolism of BC and alpha-T in ferret tissues. Three 4-week experiments were conducted using groups of 5-6 ferrets per treatment. All diets contained 0.2% BC. In Experiment 1, taurocholate was fed at concentrations of 0, 0.5, or 1%. Effects of two concentrations of dietary fat (6 and 23%) and three concentrations of protein (10, 20, and 40%) were also studied in Experiments 2 and 3, respectively. Tissues were analyzed for BC, retinoids, and alpha-T by high-pressure liquid chromatography (HPLC). Taurocholate enhanced hepatic and plasma concentrations of BC (2.3- to 3-fold), retinyl palmitate [(RP) 3.2- to 9.5-fold], retinyl stearate [(RS) 2.9- to 6- fold], and hepatic alpha-T (6- to 13- fold) at p < 0.05. High-fat diets elevated hepatic BC, RP, RS, and retinyl linoleate (RL) concentrations (2- to 3.6-fold, p < 0.05). In contrast, high-protein diets lowered hepatic RL 1.8-fold and alpha-T 8-fold (p < 0.05). Our results indicate the importance of taurocholate, fat, and protein in achieving adequate levels of vitamins A and E in mammals.
影响哺乳动物体内β-胡萝卜素（BC）、α-生育酚（α-T）和视黄醇（ROL）组织储存的饮食因素包括牛磺胆酸盐、蛋白质和脂肪。很少有研究在类似于人类的哺乳动物系统中考察这些因素对BC、视黄酯和α-T储存的影响。本研究的主要目的是调查牛磺胆酸盐（TC）、脂肪和蛋白质对雪貂组织中BC和α-T吸收与代谢的影响。进行了三个为期4周的实验，每个处理组有5至6只雪貂。所有日粮均含有0.2%的BC。在实验1中，饲喂浓度为0%、0.5%或1%的牛磺胆酸盐。在实验2和实验3中，分别研究了两种浓度的日粮脂肪（6%和23%）和三种浓度的蛋白质（10%、20%和40%）的影响。通过高压液相色谱法（HPLC）分析组织中的BC、类视黄醇和α-T。牛磺胆酸盐使肝脏和血浆中的BC浓度提高了2.3至3倍（P<0.05）、棕榈酸视黄酯[（RP）3.2至9.5倍]、硬脂酸视黄酯[（RS）2.9至6倍]以及肝脏α-T浓度提高了6至13倍（P<0.05）。高脂日粮提高了肝脏中BC、RP、RS和亚油酸视黄酯（RL）的浓度（2至3.6倍，P<0.05）。相比之下，高蛋白日粮使肝脏RL浓度降低了1.8倍，α-T浓度降低了8倍（P<0.05）。我们的结果表明牛磺胆酸盐、脂肪和蛋白质对于哺乳动物达到足够水平的维生素A和E很重要。
