Sodium bicarbonate cotransport in cultured pigmented ciliary epithelial cells.
Uptake of 22Na+ was studied in cultured bovine pigmented ciliary epithelial cells (PE) in HCO3-containing media. Two components of Na+-uptake were stimulated by intracellular acidification (NH4+-prepulse): One was amiloride-sensitive, the other DIDS-sensitive. The amiloride-sensitive component of Na+-uptake probably represents Na+/H+-exchange, which has previously been characterized in PE. The second, DIDS-sensitive component stimulated by intracellular acidification, was Cl- and HCO3--dependent. We conclude that a stilbene-sensitive, Cl--dependent Na+-HCO3--cotransport is present in PE. This transport could play an important role in aqueous humor formation.
Helbig
H
H
Institut für Klimische Physiologie, Klinikum Steglitz der Freien Universität Berlin, FRG.
Korbmacher
C
C
Nawrath
M
M
Erb
C
C
Wiederholt
M
M
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 / Q000378:metabolism*; D001692:Biological Transport; D002417:Cattle; D002478:Cells, Cultured; D002924:Ciliary Body / Q000378:metabolism*; D004847:Epithelial Cells; D010042:Ouabain / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*; D017693:Sodium Bicarbonate; D012979:Sodium Radioisotopes; D013997:Time Factors
D001639:Bicarbonates; D012979:Sodium Radioisotopes; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D010042:Ouabain; D000584:Amiloride; D017693:Sodium Bicarbonate; D012964:Sodium; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid