Wang X D
Gastroinestinal Nutrition Laboratory, USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111.
J Am Coll Nutr. 1994 Aug;13(4):314-25. doi: 10.1080/07315724.1994.10718416.
To better understand the potential function of beta-carotene (beta-C) in the prevention of cancer, greater knowledge of beta-C metabolism and a suitable animal model to mimic human beta-C metabolism are necessary. The small intestinal mucosa contains beta-C cleavage enzyme(s), thereby playing an important role in both the provitamin A activity and anti-cancer properties of beta-C. The ability of the ferret (Mustela putorius furo) to absorb intact beta-C makes it an appropriate model for studying human beta-C absorption. This article reviews the absorption and cleavage mechanisms of beta-C in both the human and the ferret. The biosynthesis of retinoic acid (RA) from beta-C via central and eccentric cleavage pathways is reviewed. The possible significance of the conversion of beta-C to RA as an anticancer mechanism is discussed.
为了更好地理解β-胡萝卜素（β-C）在预防癌症中的潜在作用，有必要更深入地了解β-C的代谢以及一个能够模拟人类β-C代谢的合适动物模型。小肠黏膜含有β-C裂解酶，因此在β-C的维生素A原活性和抗癌特性方面都发挥着重要作用。雪貂（Mustela putorius furo）吸收完整β-C的能力使其成为研究人类β-C吸收的合适模型。本文综述了人类和雪貂体内β-C的吸收和裂解机制。还综述了通过中心和偏心裂解途径由β-C生物合成视黄酸（RA）的过程。讨论了β-C转化为RA作为抗癌机制的可能意义。
