游离脂肪酸和Tween 20对犊牛和仔鸡离体小肠细胞吸收类胡萝卜素的影响

Effect of free fatty acids and Tween 20 on carotenoid uptake by small intestinal cells of calf and broiler in vitro

用犊牛和仔鸡的离体小肠细胞进行 β 胡萝卜素和黄体素的体外吸收试验 ,研究类胡萝卜素浓度、游离脂肪酸和Tween 2 0对这两种类胡萝卜素吸收的影响。结果发现 :β 胡萝卜素和黄体素的吸收均呈浓度依赖性 ,且犊牛、仔鸡的 β 胡萝卜素吸收率及犊牛的黄体素吸收率保持稳定 ,为典型的被动扩散模型 ;游离脂肪酸的添加极显著促进了类胡萝卜素的吸收 ,其中油酸的促吸收作用大于硬脂酸 ,促进 β 胡萝卜素和黄体素吸收的最佳硬脂酸与油酸的比例分别为 0∶10 0和1∶3;Tween 2 0抑制两种离体小肠细胞类胡萝卜素的吸收 ,其中对黄体素的抑制作用较大 ,对照组和Tween 2 0各组均无VA 的生成。实验表明同一因素对 β 胡萝卜素和黄体素吸收的影响程度不同。

The small intestinal mucous cells of calf and broiler were isolated and cultured with medium containing β carotene(βc)and lutein.The effect of carotenoid concentration,free fatty acids and Tween 20 on the two carotenoids uptake was determined.The uptake of βc and lutein was dose dependent,with a constant uptake percentage of βc in both cells and that of lutein in calf.The results suggested that carotenoid uptake followed passive diffusion.The uptake of both carotenoids was most significantly promoted by the addition of stearic and oleic acids.In this experiment ,the optimal ratio of stearic/oleic for the uptake of βc and lutein was 0∶100 and 1∶3,respectively.Tween 20 inhibited the uptake of both carotenoids,and lutein was more seriously inhibited.It was concluded that the same factor had different effect on the uptake of βc and lutein.