Requirements for Restitution of the Surface Epithelium of Frog Stomach After Mucosal Injury

Abstract

In frog fundic mucosae mounted in Ussing chambers, exposure to luminal 1 M NaCl for 10 min caused a sharp immediate decrease in potential difference, resistance, short circuit current, and acid secretion, but within 4-6 h these readings had returned toward control values. After initial severe destruction of surface epithelial cells, gradual morphologic restitution occurred within 4-6 h. A Ca2+-free nutrient solution and 4 mM ethylenediaminetetraacetic acid administered after injury prevented both physiologic and morphologic restitution. A Ca2+-free nutrient solution administered alone after injury prevented physiologic recovery, but although narrow gaps and lack of tight junctions were found between some cells, there was near-complete epithelial cell coverage. The addition of 2 mM Ca2+ to these tissues 3 h after injury effected rapid recovery of electrophysiologic parameters and a complete closure of the intercellular spaces. Cytochalasin B (3 X 10(-3) M nutrient) prevented physiologic recovery and mucosal restitution. Neither cycloheximide nor colchicine had any effect on the normal process of restitution. Autoradiography of [3H]thymidine incorporation showed no increase in labeling within 4 h of hyperosmolar injury. We conclude that adequate Ca2+ is required for complete restitution of gastric mucosa after hyperosmolar injury, and that restitution occurs by migration of persisting viable gastric pit cells.

Acceleration of recovery of gastric epithelial integrity by 16,16‐dimethyl prostaglandin E2

“…Similar observations have since been reported in other in vivo (Lacy & Ito, 1984;Morris & Harding, 1984;Ito & Lacy, 1985) and in vitro models (Svanes et al, 1982;Rutten & Ito, 1983;Critchlow et al, 1985). It is possible that this process is accelerated by prostaglandin pretreatment.…”

Localization of transforming growth factor alpha and its receptor in gastric mucosal cells. Implications for a regulatory role in acid secretion and mucosal renewal.

“…In support of this, epithelialization of experimentally induced gastric ulcers occurs at a rate faster than can be accounted for by mitosis (46) and rapid migration ofgastric epithelial cells to cover the ulcer has been shown (47)(48)(49). TGFa and EGF stimulate a rapid migration of proliferating keratinocytes in culture which results in expansion of colony size at a rate faster than can be accounted for by mitosis (50).…”

Stabilization of F-actin prevents cAMP-elicited Cl- secretion in T84 cells.

“…Protein synthesis, as measured by leucine incorporation, was performed according to the methods of Critchlow et al and Kastyo et al (12,13). Lactic dehydrogenase (LDH) release was measured as before (1 1).…”