Na+ effects on intracellular pH of isolated, perfused rabbit gastric mucosal surface cells.
The effects of extracellular Na+ on intracellular pH were studied by perfusing BCECF loaded gastric mucosal surface cells adherent to glass coverslips held in a spectrophotofluorometer. Removal of Na+ from a NaCl Ringer perfusate (pH 7.4) resulted in progressive intracellular acidification, which was partially blocked by amiloride. An H+ conductance did not appear to be present. Acidification induced either by Na+ removal or by a NH4 prepulse was reversed by extracellular Na+, but this effect was not completely prevented by amiloride. Amiloride significantly, but not completely, inhibited Na22 uptake by gastric mucosal surface cells. The data suggest that extracellular Na+ maintains intracellular pH of gastric mucosal surface cells through amiloride-sensitive and -insensitive pathways. In the absence of extracellular Na+, cellular acidification seemed to be partially due to Na+/H+ exchange.
Koyanagi
H
H
Department of Surgery, Wayne State University School of Medicine, Detroit, Michigan 48201.
Kraniak
J
J
Furoi
A
A
Jennings
P
P
Fromm
D
D
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D004336:Drug Antagonism; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D016018:Least-Squares Analysis; D008297:Male; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D012964:Sodium / Q000493:pharmacokinetics / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D013997:Time Factors
D000584:Amiloride; D012964:Sodium; D011188:Potassium