Hepatic versus gallbladder bile composition: In vivo transport physiology of the gallbladder in rainbow trout

Martin Grosell, M. J. O'Donnell, C. M. Wood

Research output: Contribution to journalArticle

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Ion and water transport across the teleost Oncorhynchus mykiss gallbladder were studied in vivo by comparing flow and composition of hepatic bile, collected by chronic catheter, to volume and composition of terminally collected gallbladder bile. Differences in composition were comparable with those of other vertebrates, whereas bile flow (75 μ1 · kg-1 · h-1) was below values reported for endothermic vertebrates. The gallbladder concentrates bile acids five- to sevenfold and exhibits higher net Cl- than Na+ transport in vivo, in contrast to the 1:1 transport ratio from gallbladders under saline/saline conditions. Transepithelial potential (TEP) in the presence of bile, at the apical surface, was -13 mV (bile side negative) but + 1.5 mV in the presence of saline. Bile acid in the apical saline reversed the TEP, presumably by a Donnan effect. We propose that ion transport across the gallbladder in vivo involves backflux of Na+ from blood to bile resulting in higher net Cl- than Na+ flux. This Na+ backflux is driven by a bile side negative TEP and low Na+ activity in bile due to the complexing effects of bile acids.

Original languageEnglish
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Issue number6 47-6
StatePublished - Jun 1 2000
Externally publishedYes



  • Bile acid
  • Hepatic bile flow
  • Ion and water reabsorption
  • Teleost freshwater fish
  • Transepithelial potential

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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