The effects of bicarbonate and hydroxyl ions on chloride transport by toad bladders.
The association between Cl-, HCO3- and H+ transported by toad bladders was investigated. Net mucosal to serosal Cl- transport by Colombian toad bladders was stimulated by incubation in HCO3- free solutions. In addition, when Colombian or Dominican toad bladders were exposed to low HCO3- concentrations on the mucosal side and 25 mM HCO3- on the serosal side, net mucosal leads to serosal Cl- transport was induced. Neither acetazolamide nor cyanide significantly inhibited Cl- transport under these conditions. The presence of a pH gradient, more acid on the mucosal side, also induced net mucosal leads to serosal Cl- transport. The results suggest that Cl- transport by toad bladders may occur by exchange with HCO3- or OH-; this process may not require carbonic anhydrase or oxidative metabolism. The Cl- transport by toad bladders is qualitatively different from the electrogenic Cl- transport of the thick limb of Henle's loop, but may be similar to a process which occurs in other portions of the nephron.
D000086:Acetazolamide / Q000494:pharmacology; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology*; D002024:Bufo marinus; D002712:Chlorides / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013045:Species Specificity; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism*
D001639:Bicarbonates; D002712:Chlorides; D000086:Acetazolamide