QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by HENRY, R. P. Articles by CAMERON, J. N. Search for Related Content PubMed Articles by HENRY, R. P. Articles by CAMERON, J. N.

Journal of Experimental Biology 103,205-223 (1983)
Published by Company of Biologists 1983

The Role of Carbonic Anhydrase in Respiration, Ion Regulation and Acid-Base Balance in the Aquatic Crab Calunectes Sapidus and the Terrestrial Crab Gecarcinus Lateraus

RAYMOND P. HENRY ¹ and JAMES N. CAMERON ²

¹ Departments of Zoology and Marine Studies, The University of Texas at Austin, Marine Science Institute Port Aransas, Texas 78373; Department of Physiology G4, The University of Pennsylvania School of Medicine Philadelphia, Pennsylvania 19104
² Departments of Zoology and Marine Studies, The University of Texas at Austin, Marine Science Institute Port Aransas, Texas 78373

The enzyme carbonic anhydrase (CA), which is concentrated mainly in the osmoregulatory tissue of the gills, appears to be required for ion regulation but not for CO₂ excretion. An injection of the CA inhibitor acetazolamide produced an inhibition of between 90 and 100%, which took 6 h to be fully effective, and 48-96 h to wear off. During the period of inhibition in Callinectes sapidus there was no change in either O₂ uptake or CO₂ excretion, nor was there any increase in blood P_coco2. In blue crabs acclimated to 250 mosM salinity, at which the animals are ion regulators, inhibition of CA caused both Na⁺ and Cl^- concentrations in the blood to be lowered, with Cl^- being lowered to a greater degree. As a result of an increase in the Na⁺-Cl^- difference the animal experienced a ‘metabolic’ alkalosis: elevated blood pH and HCO₃^- at constant Pco₂. The data are consistent with the hypothesis that branchial CA functions in providing H⁺ and HCO₃^- as counterions for Na⁺ and Cl^- transport through the hydration of respiratory CO₂.

In the terrestrial Gecarcinus lateralis, inhibition of CA caused an increase in blood P_co2, but did not alter O₂ uptake or CO₂ excretion. After an initial acidosis, blood pH and HCO₃^- increased and remained elevated. Blood osmolality, Na⁺, Cl^- and Ca²⁺ concentrations all increased, and the animals experienced a high rate of mortality. These data suggest that CA in the land crab is also important in blood ion regulation, probably to combat desiccation.

Key words: Carbonic anhydrase, acid-base regulation, crustaceans

Submitted on July 30, 1981
Accepted on September 21, 1982

This article has been cited by other articles:

				G. Lannig, A. S. Cherkasov, H.-O. Portner, C. Bock, and I. M. Sokolova Cadmium-dependent oxygen limitation affects temperature tolerance in eastern oysters (Crassostrea virginica Gmelin) Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2008; 294(4): R1338 - R1346. [Abstract] [Full Text] [PDF]

				M. Tresguerres, S. K. Parks, S. E. Sabatini, G. G. Goss, and C. M. Luquet Regulation of ion transport by pH and [HCO3-] in isolated gills of the crab Neohelice (Chasmagnathus) granulata Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2008; 294(3): R1033 - R1043. [Abstract] [Full Text] [PDF]

				R. P. Henry Functional evidence for the presence of a carbonic anhydrase repressor in the eyestalk of the euryhaline green crab Carcinus maenas J. Exp. Biol., July 1, 2006; 209(13): 2595 - 2605. [Abstract] [Full Text] [PDF]

				R. Henry Environmentally mediated carbonic anhydrase induction in the gills of euryhaline crustaceans J. Exp. Biol., January 3, 2001; 204(5): 991 - 1002. [Abstract] [PDF]