[Pinocytotic route of calcium transport through the intestinal epithelium in newborn rats].

A comparative electron microscope study has been made on the localization of calcium in the epithelium of duodenum in chicks and rats during cation absorption. The main amount of calcium in animal epithelium concentrated in the brush border region and lateral membranes. In new-born rats, calcium is localized on the inner surface of pinocytic vesicles, which are moving from the apical surface through the area above the nucleus towards the lateral plasmatic membrane of enterocytes.