Fournier P, Dupuis Y, Fournier A
Ann Nutr Aliment. 1976;29(5):421-38.
The absorption of calcium corresponds to a strictly determined mechanism inhibited by phosphates and activited by carbohydrates. We investigate in what extent the absorption of milk calcium from various species has the same proceeding. 4 months old rats are given orally solutions of CaCl2 alone or in combination with sodium dihydrogen phosphate or lactose or these both compounds. We compare calcium absorption of these solutions to that of milk from woman, cow or sow, or to dilutions of these two latter milks. All these fluids are dosed so that they correspond each other by their respective content in total calcium, total phosphorus and lactose. Each solution contains 45Ca. Blood samples 1,30, 4, 6 and 24 hours after ingestion allow establishing the variations of plasma radioactivity. Rats are sacrified after 24 hours. In certain cases, samples from digestive tube contents and feces provide a coefficient of calcium absorption. The osseous retention is obtained from femur radioactivity. In breif, we may consider that milks from cow and sow provide calcium the absorption of which is settled after their respective content of total phosphorus and lactose. Opposed effects of these inhibitors and activators of calcium absorption compensate so that calcium from these milks is just a little better utilized by adult rat than calcium from an isocalcic solution of CaCl2. Calcium from woman milk, rich in carbohydrates, poor in total phosphorus is better absorbed than that from the two latters, however less than we might expect from its high lactose content. We may wonder that calcium utilization from cow milk is as moderate as that of a solution of CaCl2. But skeleton mineralization which may be fulfilled by milk is made better because of that: it is not chloride but calcium phosphate which ensures this mineralization, a phosphate which alone would impair this mineralization without the compensative role of lactose.
钙的吸收遵循一种严格确定的机制，该机制受到磷酸盐的抑制并由碳水化合物激活。我们研究了不同物种的乳钙吸收过程在多大程度上相同。给4个月大的大鼠口服单独的氯化钙溶液，或与磷酸二氢钠、乳糖或这两种化合物混合的溶液。我们将这些溶液的钙吸收情况与来自女性、奶牛或母猪的牛奶，或后两种牛奶的稀释液的钙吸收情况进行比较。所有这些液体的给药量使得它们在总钙、总磷和乳糖含量上相互对应。每种溶液都含有45Ca。摄入后1、3、4、6和24小时采集血样，以确定血浆放射性的变化。24小时后处死大鼠。在某些情况下，从消化管内容物和粪便中取样可得出钙吸收系数。通过股骨放射性获得骨潴留情况。简而言之，我们可以认为奶牛和母猪产的牛奶提供的钙，其吸收情况取决于它们各自的总磷和乳糖含量。钙吸收的这些抑制剂和激活剂的相反作用相互抵消，因此成年大鼠对这些牛奶中的钙的利用率仅略高于氯化钙等钙溶液中的钙。人乳中碳水化合物丰富、总磷含量低，其钙的吸收比后两种牛奶中的钙更好，然而却低于我们根据其高乳糖含量所预期的吸收情况。我们可能会奇怪，牛奶中钙的利用率为何与氯化钙溶液的利用率一样适度。但正是因为这样，牛奶实现的骨骼矿化效果更好：确保这种矿化的不是氯化物而是磷酸钙，单独的磷酸盐会损害这种矿化，而乳糖起到了补偿作用。
