The Non-Essentiality of Sodium Ions for Intestinal Calcium Transport. ∗

Summary

Using an in vitro everted duodenal preparation from the rat, an assessment was made of the essentiality of the sodium ion in calcium transport. Choline chloride completely replaced sodium chloride whereas LiCl was partially inhibitory to this system. In confirmation of other work, sodium ion was shown to be essential for glucose transport. These data would indicate that sodium ion is not an essential requirement for active calcium transport, and would tend to separate the calcium transport system from several other transport systems.