The unique ultrastructure of secretory membranes in gastric parietal cells depends upon the presence of H , K -ATPase

Abstract

Ion transporters play a central role in gastric acid secretion. To determine whether some of these transporters are necessary for the normal ultrastructure of secretory membranes in gastric parietal cells, mice lacking transporters for H+, K+, Cl-, and Na+ were examined for alterations in volume density (Vd) of basolateral, apical, tubulovesicular and canalicular membranes, microvillar dimensions, membrane flexibility, and ultra-structure. In mice lacking Na+/H+ exchanger 1 (NHE1) or the Na+-K+-2Cl- cotransporter (NKCC1), the ultra-structure and Vd of secretory membranes and the secretory canalicular to tubulovesicular membrane ratio (SC/TV), a morphological correlate of secretory activity, ..