Functional heterogeneity of parietal cells along the pit-gland
axis.
Karam, Sherif M., Xuebiao Yao, and John G. Forte.
Department of Anatomy, Faculty of Medicine, Kuwait,University,
Safat, 13110, Kuwait and Department of Molecular and Cell Biology,
University of California, Berkeley, CA 94720, USA
APStracts 3:0167G, 1996.
The gastric epithelium forms numerous short pits continuous with long
tubular glands divisible into isthmus, neck and base regions.
Parietal cells are produced in the isthmus and migrate down to the
neck and base regions as they mature and age. Stimulation of parietal
cells is manifest by translocation of H+,K+-ATPase-rich
tubulovesicles (TV) from the cytoplasm into the secretory/apical (SA)
membrane. Here we used rabbit isolated gastric glands to examine the
physiological responses of parietal cells to graded levels of
stimulation. Quantitative morphometry was used to evaluate parietal
cell response along the longitudinal axis of the gland. Acid
secretion as estimated by 14C-aminopyrine uptake was well correlated
with parallel enzymatic and immunoblot assays for the redistribution
of H+, K+-ATPase from TV to SA membranes. These responses also
correlated well with morphological transformations of parietal cells
within the isthmus and neck regions of the gastric gland; however,
parietal cells in the base of the gland showed very little
morphological change with any of the stimuli used. The poor
responsiveness of basal parietal cells is in agreement with
observations on intact mucosa and suggests that older parietal cells
may serve some function other than acid secretion.
Received 10 April 1996; accepted in final form 17 August 1996.
APS Manuscript Number G125-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996