[Changes in basolateral membrane of villus cells in the rat small intestine at low pH]

The basolateral membrane of isolated villus cells of rat small intestine was isolated and was used to investigate the structural changes as well as the simultaneous alterations of its protein pattern at low pH-value. For this purpose the alterations, which occur on the membrane under the influence of HCL, were studied in the electron microscope (negative staining) and by SDS-Polyacryl-amid-Gel electrophoresis. The results show firstly a total disintegration of the membrane and the formation of very uniformly shaped fragments and secondly the absence of protein bands in the fragments in comparison to the protein pattern of the intact membrane. Extraction of more extensive protein bands could not be demonstrated. Possible conclusions concerning the structure of the basolateral membrane and parallels to the reaction of Erythrocyte membrane under the same conditions are discussed.