EXISTENCE OF A NA+-ACTIVATED, FUROSEMIDE INHIBITED ATPASE ACTIVITY IN RAT INTESTINAL-MUCOSA

  • 1 January 1982
    • journal article
    • research article
    • Vol. 41  (11) , 1037-1043
Abstract
An ouabain-insensitive, Mg2+-dependent, Na+-stimulated ATPase activity which is inhibited by furosemide was found in the mucosal homogenate of rat small intestine. The subcellular localization of this ATPase activity was studied by means of isolated purified brush borders and basolateral plasma membranes. A nearly identical distribution of Na+-activated and (Na+, K+)-activated ATPase within the epithelial cells is suggested. Under conditions of alloxan and streptozotocin diabetes, an increase of both ATPase activities can be found only in the basolateral plasma membranes. These observations agree well with the convective model of intestinal absorption.