Intestinal anion exchange in marine fish osmoregulation

Research output: Contribution to journalArticle

177 Citations (Scopus)

Abstract

Despite early reports, dating back three quarters of a century, of high total CO2 concentrations in the intestinal fluids of marine teleost fishes, only the past decade has provided some insight into the functional significance of this phenomenon. It is now being recognized that intestinal anion exchange is responsible for high luminal HCO3- and CO32- concentrations while at the same time contributing substantially to intestinal Cl- and thereby water absorption, which is vital for marine fish osmoregulation. In species examined to date, the majority of HCO3- secreted by the apical anion exchange process is derived from hydration of metabolic CO2 with the resulting H+ being extruded via a Na+:H+ exchange mechanism in the basolateral membrane. The basolateral H+ extrusion is critical for the apical anion exchange and relies on the Na+ gradient established by the Na+-K+-ATPase. TMs enzyme thereby ultimately fuels the secondary active transport of HCO3 - and Cl- by the apical anion exchanger. High cellular HCO3- concentrations (>10 mmol l-1) are required for the anion exchange process and could be the result of both a high metabolic activity of the intestinal epithelium and a close association of the anion exchange protein and the enzyme carbonic anhydrase. The anion exchange activity in vivo is likely most pronounced in the anterior segment and results in net intestinal acid absorption. In contrast to other water absorbing vertebrate epithelia, the marine teleost intestine absorbs what appears to be a hypertonic fluid to displace diffusive fluid loss to the marine environment.

Original languageEnglish
Pages (from-to)2813-2827
Number of pages15
JournalJournal of Experimental Biology
Volume209
Issue number15
DOIs
StatePublished - Aug 1 2006

Fingerprint

Osmoregulation
osmoregulation
anion exchange
marine fish
Anions
ion exchange
Fishes
fish
antiporters
teleost
fluid
sodium-potassium-exchanging ATPase
active transport
enzyme
carbonate dehydratase
Antiporters
intestinal mucosa
enzymes
Carbonic Anhydrases
extrusion

Keywords

  • Acidic absorbate
  • Cl/HCO exchange
  • Hypertonic water absorption
  • Secondary active Cl and HCO transport

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Agricultural and Biological Sciences (miscellaneous)

Cite this

Intestinal anion exchange in marine fish osmoregulation. / Grosell, Martin.

In: Journal of Experimental Biology, Vol. 209, No. 15, 01.08.2006, p. 2813-2827.

Research output: Contribution to journalArticle

@article{38065a19e2c244f780875d313806b15a,
title = "Intestinal anion exchange in marine fish osmoregulation",
abstract = "Despite early reports, dating back three quarters of a century, of high total CO2 concentrations in the intestinal fluids of marine teleost fishes, only the past decade has provided some insight into the functional significance of this phenomenon. It is now being recognized that intestinal anion exchange is responsible for high luminal HCO3- and CO32- concentrations while at the same time contributing substantially to intestinal Cl- and thereby water absorption, which is vital for marine fish osmoregulation. In species examined to date, the majority of HCO3- secreted by the apical anion exchange process is derived from hydration of metabolic CO2 with the resulting H+ being extruded via a Na+:H+ exchange mechanism in the basolateral membrane. The basolateral H+ extrusion is critical for the apical anion exchange and relies on the Na+ gradient established by the Na+-K+-ATPase. TMs enzyme thereby ultimately fuels the secondary active transport of HCO3 - and Cl- by the apical anion exchanger. High cellular HCO3- concentrations (>10 mmol l-1) are required for the anion exchange process and could be the result of both a high metabolic activity of the intestinal epithelium and a close association of the anion exchange protein and the enzyme carbonic anhydrase. The anion exchange activity in vivo is likely most pronounced in the anterior segment and results in net intestinal acid absorption. In contrast to other water absorbing vertebrate epithelia, the marine teleost intestine absorbs what appears to be a hypertonic fluid to displace diffusive fluid loss to the marine environment.",
keywords = "Acidic absorbate, Cl/HCO exchange, Hypertonic water absorption, Secondary active Cl and HCO transport",
author = "Martin Grosell",
year = "2006",
month = "8",
day = "1",
doi = "10.1242/jeb.02345",
language = "English",
volume = "209",
pages = "2813--2827",
journal = "Journal of Experimental Biology",
issn = "0022-0949",
publisher = "Company of Biologists Ltd",
number = "15",

}

TY - JOUR

T1 - Intestinal anion exchange in marine fish osmoregulation

AU - Grosell, Martin

PY - 2006/8/1

Y1 - 2006/8/1

N2 - Despite early reports, dating back three quarters of a century, of high total CO2 concentrations in the intestinal fluids of marine teleost fishes, only the past decade has provided some insight into the functional significance of this phenomenon. It is now being recognized that intestinal anion exchange is responsible for high luminal HCO3- and CO32- concentrations while at the same time contributing substantially to intestinal Cl- and thereby water absorption, which is vital for marine fish osmoregulation. In species examined to date, the majority of HCO3- secreted by the apical anion exchange process is derived from hydration of metabolic CO2 with the resulting H+ being extruded via a Na+:H+ exchange mechanism in the basolateral membrane. The basolateral H+ extrusion is critical for the apical anion exchange and relies on the Na+ gradient established by the Na+-K+-ATPase. TMs enzyme thereby ultimately fuels the secondary active transport of HCO3 - and Cl- by the apical anion exchanger. High cellular HCO3- concentrations (>10 mmol l-1) are required for the anion exchange process and could be the result of both a high metabolic activity of the intestinal epithelium and a close association of the anion exchange protein and the enzyme carbonic anhydrase. The anion exchange activity in vivo is likely most pronounced in the anterior segment and results in net intestinal acid absorption. In contrast to other water absorbing vertebrate epithelia, the marine teleost intestine absorbs what appears to be a hypertonic fluid to displace diffusive fluid loss to the marine environment.

AB - Despite early reports, dating back three quarters of a century, of high total CO2 concentrations in the intestinal fluids of marine teleost fishes, only the past decade has provided some insight into the functional significance of this phenomenon. It is now being recognized that intestinal anion exchange is responsible for high luminal HCO3- and CO32- concentrations while at the same time contributing substantially to intestinal Cl- and thereby water absorption, which is vital for marine fish osmoregulation. In species examined to date, the majority of HCO3- secreted by the apical anion exchange process is derived from hydration of metabolic CO2 with the resulting H+ being extruded via a Na+:H+ exchange mechanism in the basolateral membrane. The basolateral H+ extrusion is critical for the apical anion exchange and relies on the Na+ gradient established by the Na+-K+-ATPase. TMs enzyme thereby ultimately fuels the secondary active transport of HCO3 - and Cl- by the apical anion exchanger. High cellular HCO3- concentrations (>10 mmol l-1) are required for the anion exchange process and could be the result of both a high metabolic activity of the intestinal epithelium and a close association of the anion exchange protein and the enzyme carbonic anhydrase. The anion exchange activity in vivo is likely most pronounced in the anterior segment and results in net intestinal acid absorption. In contrast to other water absorbing vertebrate epithelia, the marine teleost intestine absorbs what appears to be a hypertonic fluid to displace diffusive fluid loss to the marine environment.

KW - Acidic absorbate

KW - Cl/HCO exchange

KW - Hypertonic water absorption

KW - Secondary active Cl and HCO transport

UR - http://www.scopus.com/inward/record.url?scp=33748434747&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33748434747&partnerID=8YFLogxK

U2 - 10.1242/jeb.02345

DO - 10.1242/jeb.02345

M3 - Article

C2 - 16857865

AN - SCOPUS:33748434747

VL - 209

SP - 2813

EP - 2827

JO - Journal of Experimental Biology

JF - Journal of Experimental Biology

SN - 0022-0949

IS - 15

ER -