TY - JOUR
T1 - Ionic requirements for H+ secretion and membrane elaboration in frog oxyntic cells
AU - Logsdon, C. D.
AU - Machen, T. E.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1982
Y1 - 1982
N2 - We have tested whether the ions K+, Na+, or Cl- are required for either initiation or maintenance of secretory parameters of amphibian oxyntic cells. In vitro mucosal preparations were washed repeatedly in Ringer solution lacking the ion question either before (i.e., resting tissues) or after addition of stimulants. Electrophysiology, H+ secretion, and morphology (morphometric analysis of oxyntic cells) were monitored. Na+ or K+ stimulation of resting tissues in Na+ or K+-free solutions elicited no H+ secretion; there was only a small increase (~twofold) in secretory surface density (S(V)) (during control S(V) increased sixfold). The Na+-free effects were partially reversed by high [K+]. In secreting tissues, Na+ or K+-free solutions caused H+ secretion to decrease to zero. Gastric glands from these mucosae appeared 'occluded': the gland lumen was filled with apposed apical projections of oxyntic cells. Cl- stimulation after Cl- removal initiated low levels of H+ secretion. Morphologically the cells either appeared normally stimulated (S(V) increased eightfold) or, more rarely, took on the occluded appearance. Cl- removal from stimulated mucosae decreased H+ secretion ~50%, but the cells were normally elaborate. We conclude that K+ is required for the initiation of H+ secretion and the stimulated morphology change; the effects of Na+ removal are due to effects on internal [K; Cl- is not required. The occurrence of occluded morphology under conditions of inhibited H+ and H2O secretion indicates a role for water flow in the maintenance of stimulated morphology.
AB - We have tested whether the ions K+, Na+, or Cl- are required for either initiation or maintenance of secretory parameters of amphibian oxyntic cells. In vitro mucosal preparations were washed repeatedly in Ringer solution lacking the ion question either before (i.e., resting tissues) or after addition of stimulants. Electrophysiology, H+ secretion, and morphology (morphometric analysis of oxyntic cells) were monitored. Na+ or K+ stimulation of resting tissues in Na+ or K+-free solutions elicited no H+ secretion; there was only a small increase (~twofold) in secretory surface density (S(V)) (during control S(V) increased sixfold). The Na+-free effects were partially reversed by high [K+]. In secreting tissues, Na+ or K+-free solutions caused H+ secretion to decrease to zero. Gastric glands from these mucosae appeared 'occluded': the gland lumen was filled with apposed apical projections of oxyntic cells. Cl- stimulation after Cl- removal initiated low levels of H+ secretion. Morphologically the cells either appeared normally stimulated (S(V) increased eightfold) or, more rarely, took on the occluded appearance. Cl- removal from stimulated mucosae decreased H+ secretion ~50%, but the cells were normally elaborate. We conclude that K+ is required for the initiation of H+ secretion and the stimulated morphology change; the effects of Na+ removal are due to effects on internal [K; Cl- is not required. The occurrence of occluded morphology under conditions of inhibited H+ and H2O secretion indicates a role for water flow in the maintenance of stimulated morphology.
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U2 - 10.1152/ajpgi.1982.242.4.g388
DO - 10.1152/ajpgi.1982.242.4.g388
M3 - Article
C2 - 6978079
AN - SCOPUS:17444453682
SN - 0193-1857
VL - 5
SP - G388-G399
JO - American Journal of Physiology - Gastrointestinal and Liver Physiology
JF - American Journal of Physiology - Gastrointestinal and Liver Physiology
IS - 4
ER -