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PubMed · 2410297

Structure-function relationships in H+-secreting epithelia.

K M Madsen·C C Tisher
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Abstract

Stimulation or inhibition of H+ secretion has been associated with characteristic ultrastructural changes in various epithelial cells, including the parietal cell of the gastric mucosa, the carbonic anhydrase (CA)-rich cell of the turtle urinary bladder, and the intercalated (I) cell of the mammalian collecting duct. An electroneutral potassium-activated H+-ATPase is responsible for H+ secretion in the stomach, whereas acidification in the turtle bladder and the mammalian collecting duct is mediated by an electrogenic H+-translocating ATPase. Despite these differences, the parietal cell, the CA-rich cell, and the I cell have several morphological features in common. They are rich in mitochondria, contain numerous tubulovesicular membrane structures in the apical region of the cell, and possess a variable number of microprojections on the luminal surface. After stimulation of H+ secretion there is a significant increase in the surface area of the apical membrane concomitant with a decrease in the tubulovesicular membrane compartment in these cells, as revealed by morphometric analysis. These findings suggest that membrane (possibly containing an H+ pump) is being transferred from the tubulovesicular compartment to the apical plasma membrane on stimulation of H+ secretion. A hypothesis of membrane recycling is proposed to account for the observed morphological changes.

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AmphibiansAnimalsCarbonic AnhydrasesEpitheliumIon ChannelsKidney Tubules, CollectingMicroscopy, ElectronParietal Cells, GastricProtonsRabbitsRatsTurtlesUrinary BladderJournal ArticleResearch Support, U.S. Gov't, P.H.S.Review

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K M Madsen, C C Tisher. 1985. Structure-function relationships in H+-secreting epithelia.. https://pubmed.ncbi.nlm.nih.gov/2410297/

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