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动物实验提示老龄化影响膳食维生素A在肠道的变化及吸收后的进程。Hollander等在动物灌流实验中发现年龄和维生素A吸收率间几乎呈直线正相关。Sundboom等观察到,老龄化降低小鼠肝脏对维生素A的摄取。由于已形成的维生素A(视黄醇、视黄酯)和维生素A原化合物(类胡萝卜素)的吸收和吸收后的代谢与脂质的消化和吸收的整个过程有关,膳食脂肪代谢减弱被认为可能是导致老龄化过程中视黄醛衍生物和类胡萝卜素变化的原因。例如,
Animal experiments suggest that aging affects the changes of dietary vitamin A in the gut and the process of absorption. Hollander et al found that there was almost a linear correlation between age and vitamin A absorption rate in animal perfusion experiments. Sundboom et al observed that aging reduces vitamin A uptake in the liver of mice. The reduced metabolism of dietary lipids is thought to be due to the absorption and uptake of already formed vitamin A (retinol, retinyl esters) and vitamin A proto-compounds (carotenoids), which are related to the overall process of lipid digestion and absorption It may be the cause of the changes of retinoids and carotenoids during the aging process. E.g,