Influence of Cl- on pH(i) in oxynticopeptic cells of in vitro frog gastric mucosa.
The effect of Cl- on intracellular pH (pH(i)) was studied using sheets of frog (Rana catesbeiana) fundic mucosa in which oxynticopeptic cells were selectively loaded with the acetomethoxy ester form of the pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF/AM). Before the measurement of pH(i), tissues were exposed to either 10(-5) M forskolin in the serosal solution (stimulated tissues) or 3 x 10(-4) omeprazole in the serosal solution (inhibited tissues). In HCO3- and N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffers, pH(i) increased significantly after removal of Cl- from serosal and luminal solution, both in stimulated and inhibited tissues. The presence of Cl- in the luminal solution prevented this rise in pHi, an effect abolished by serosal 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS, 3 x 10(-4) M) but not by serosal amiloride (10(-3)M). In the presence of serosal Cl-, pH(i) increased after exposure to serosal DIDS, more prominently in the stimulated than in the inhibited tissues. These results confirm the presence of a Cl(-)-HCO3-exchanger in the basolateral membrane of oxynticopeptic cells in intact sheets of mucosa and suggest that luminal Cl- contributes to the regulation of pH(i) in oxynticopeptic cells.
Yanaka
A
A
Department of Surgery, Beth Israel Hospital, Harvard Medical School, Boston, Massachusetts.
Carter
K J
KJ
Lee
H H
HH
Silen
W
W
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology*; D005576:Colforsin / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D005748:Gastric Fundus / Q000187:drug effects / Q000502:physiology*; D005753:Gastric Mucosa / Q000187:drug effects / Q000502:physiology*; D006531:HEPES / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009853:Omeprazole / Q000494:pharmacology; D011892:Rana catesbeiana
D001639:Bicarbonates; D002712:Chlorides; D005576:Colforsin; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D000584:Amiloride; D009853:Omeprazole; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D006531:HEPES