Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-4-10
pubmed:abstractText
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.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
638-45
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Rat lung carbonic anhydrase: activity, localization, and isozymes.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.