HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Corrigendum A corrigendum has been published All Versions of this Article: 295/2/R704    most recent 90337.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Evans, D. H. PubMed PubMed Citation Articles by Evans, D. H.

REVIEW

COMPARATIVE AND EVOLUTIONARY PHYSIOLOGY
August Krogh Distinguished Lectureship of the APS Comparative and Evolutionary Physiology Section, 2008

Teleost fish osmoregulation: what have we learned since August Krogh, Homer Smith, and Ancel Keys

Department of Zoology, University of Florida, Gainesville, Florida; and Mt. Desert Island Biological Laboratory, Salisbury Cove, Maine

Submitted 2 April 2008 ; accepted in final form 2 June 2008

ABSTRACT

In the 1930s, August Krogh, Homer Smith, and Ancel Keys knew that teleost fishes were hyperosmotic to fresh water and hyposmotic to seawater, and, therefore, they were potentially salt depleted and dehydrated, respectively. Their seminal studies demonstrated that freshwater teleosts extract NaCl from the environment, while marine teleosts ingest seawater, absorb intestinal water by absorbing NaCl, and excrete the excess salt via gill transport mechanisms. During the past 70 years, their research descendents have used chemical, radioisotopic, pharmacological, cellular, and molecular techniques to further characterize the gill transport mechanisms and begin to study the signaling molecules that modulate these processes. The cellular site for these transport pathways was first described by Keys and is now known as the mitochondrion-rich cell (MRC). The model for NaCl secretion by the marine MRC is well supported, but the model for NaCl uptake by freshwater MRC is more unsettled. Importantly, these ionic uptake mechanisms also appear to be expressed in the marine gill MRC, for acid-base regulation. A large suite of potential endocrine control mechanisms have been identified, and recent evidence suggests that paracrines such as endothelin, nitric oxide, and prostaglandins might also control MRC function.

gill salt transport; mitochondrion-rich cell; endothelin