title: Ion transport by the urinary bladder of the gobiid teleost, Gillichthys mirabilis.
abstract: Transport characteristics of the two epithelial cell types lining the urinary bladder of the goby can be studied in Ussing-type chambers. Cuboidal cell regions from seawater- and 5% seawater-acclimated fish exhibit little mucosal-to-serosal Na or Cl transport. In contrast, columnar cell regions from both seawater- and 5% seawater-acclimated fish transport substantial amounts of Na and Cl. Whereas all electrolyte transport in 5% seawater-acclimated fish is electrically silent (neutral), columnar cell regions from seawater-acclimated fish possess an electrogenic Na transport component in addition to the neutral transport. Columnar cell regions also possess a Cl/Cl exchange diffusion mechanism. Neutral Na and Cl transport are not altered in response to external salinity; electrogenic transport varies both with acclimation to salinity and season. Reabsorption of Na and Cl from urine reduces excretory losses of these ions from 5% seawater-acclimated fish and drives urinary bladder water reabsorption in seawater-acclimated fish.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D002712:Chlorides / Q000378:metabolism*; D004553:Electric Conductivity; D005399:Fishes / Q000502:physiology*; D008564:Membrane Potentials; D012621:Seasons; D012964:Sodium / Q000378:metabolism*; D001743:Urinary Bladder / Q000502:physiology*; D014556:Urine / Q000502:physiology; D014882:Water-Electrolyte Balance
chemical_list: D002712:Chlorides; D012964:Sodium