离体小肠粘膜细胞对类胡萝卜素的吸收

UPTAKE OF CAROTENOIDS BY INTESTINAL MUCOUS CELLS OF LAYERS AND GOATS IN VITRO

选用两种有代表性的类胡萝卜素（β－胡萝卜素和黄体素）分别用蛋鸡、山羊的离体小肠细胞进行体外吸收实验。结果表明：β－胡萝卜素和黄体素的吸收均呈浓度依赖性，且β－胡萝卜素吸收率保持稳定（Ｐ＞０．０５）；培养温度对蛋鸡离体小肠粘膜细胞类胡萝卜素吸收无显著影响，而极显著地影响了山羊对黄体素和高浓度（≥１５μｍｏｌ／Ｌ）β－胡萝卜素的吸收；Ｔｗｅｅｎ２０对两种类胡萝卜素均有抑制作用，其中对黄体素抑制作用较大；体积分数（φ）为０．３％的Ｔｗｅｅｎ２０可能阻断了β－胡萝卜素转化为维生素Ａ；０．５ｍｏｌ／Ｌ的根皮素抑制了β－胡萝卜素的吸收而对黄体素吸收起促进作用（Ｐ＜０．０１）。

Uptake of βcarotene and lutein by layers and goats was studied in vitro. The result showed uptake of βcarotene and lutein was concentrationdependent and a constant uptake percentage of βcarotene was observed. This suggested carotenoids were uptaken by passive diffusion mechanism. Uptake of carotenoids by cells of layer was temperatureindependent while uptake of lutein and βcarotene at high concentration by goats was affected significantly by incubation temperature. Tween 20 inhibited uptake of carotenoids among which lutein was more heavily inhibited than βcarotene. In addition inhibition of βcarotene and promotion of lutein by phloretin were first reported.