Journal of Applied Physiology Track the topics, authors and articles important to you
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 60: 638-645, 1986;
8750-7587/86 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Henry, R. P.
Right arrow Articles by Storey, B. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Henry, R. P.
Right arrow Articles by Storey, B. T.

Journal of Applied Physiology, Vol 60, Issue 2 638-645, Copyright © 1986 by American Physiological Society

ARTICLES

Rat lung carbonic anhydrase: activity, localization, and isozymes

R. P. Henry, S. J. Dodgson, R. E. Forster and B. T. Storey

Carbonic anhydrase activity in rat lungs perfused free of blood was localized by homogenization of the tissue followed by differential centrifugation. Four fractions were obtained from the homogenate, a cell debris pellet with a mitochondrial pellet and a microsomal pellet with a clear cytosol supernatant. The last named fraction contained 67% of the total enzyme activity; the cell debris contained 18%, and the mitochondrial and microsomal contained 8 and 7%, respectively. Of the 33% of enzyme activity associated with the pellet fraction, 25% could be experimentally defined as membrane associated by its solubilization with 0.3 M tris-(hydroxymethyl) aminoethane sulfate buffer. The remainder was defined as membrane bound. Purification of the soluble carbonic anhydrase from the lung yielded two isozymes with electrophoretic and inhibitor sensitivities apparently identical with the blood isozymes. Hemoglobin analysis showed that the lung isozymes could not have included more than 0.03% enzyme from blood contamination. The carbonic anhydrase activity present in the whole rat lung would give an average acceleration of the CO2 hydration reaction under physiological conditions over the uncatalyzed rate of 122, sufficient to maintain equilibration between CO2 and plasma HCO3- during blood transit of the lung. If the membrane-associated activity is mostly on the plasma membrane of the endothelial cells and available to the capillary blood, it would be sufficient to give this acceleration. We suggest that the possible source of this membrane-associated activity might be adsorption from the blood of carbonic anhydrase liberated by erythrocyte lysis.


This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
H. Schulz, A. Schulz, G. Eder, and J. Heyder
Labeled carbon dioxide (C18O2): an indicator gas for phase II in expirograms
J Appl Physiol, November 1, 2004; 97(5): 1755 - 1762.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
Y.-H. H. Lien and L.-W. Lai
Respiratory acidosis in carbonic anhydrase II-deficient mice
Am J Physiol Lung Cell Mol Physiol, February 1, 1998; 274(2): L301 - L304.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online