Inhibition of converting enzyme activity by acute hypoxia in dogs

Details

Serval ID
serval:BIB_05F0D5BD8142
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Inhibition of converting enzyme activity by acute hypoxia in dogs
Journal
Journal of Applied Physiology
Author(s)
Stalcup  S. A., Lipset  J. S., Legant  P. M., Leuenberger  P. J., Mellins  R. B.
ISSN
0161-7567 (Print)
Publication state
Published
Issued date
02/1979
Volume
46
Number
2
Pages
227-34
Notes
Journal Article
Research Support, U.S. Gov't, P.H.S.
Retracted Publication --- Old month value: Feb
Abstract
We studied the effect of a change in oxygen tension on converting enzyme activity in anesthetized, paralyzed, catheterized dogs ventilated with room air, 100% O2, and hypoxic gas mixtures. Bradykinin was continuously infused into the femoral vein and simultaneous samples drawn from the pulmonary artery and left atrium; bradykinin was extracted into ethanol and measured by radioimmunoassay. Clearance of bradykinin by lung converting enzyme decreased from 96% at PaO2 levels above 95 Torr to 0% below 26 Torr. Inhibition of enzyme activity was rapid in onset (less than 2 min), closely correlated with PaO2 (r = 0.92, P less than 0.001), and reversible within 2 min after return to room air breathing. Converting enzyme activity of the systemic vascular bed was also inhibited by hypoxia; kininase I activity was unaffected by oxygen tension. Although arterial bradykinin concentrations in the range of 0.5 ng/ml produced hypotension in normoxic animals, elevations to 30 ng/ml had no hypotensive effect in hypoxic dogs. During acute hypoxia, venous bradykinin will pass through the lung unmetabolized, and local levels of angiotensin II and bradykinin will vary in vascular beds with different oxygen tensions, providing a finely-graded mechanism for blood flow regulation.
Keywords
Animals Bradykinin/metabolism Dogs Lung/*enzymology *Oxygen Peptidyl-Dipeptidase A/*metabolism Radioimmunoassay *Respiration
Pubmed
Web of science
Create date
25/01/2008 9:50
Last modification date
20/08/2019 12:28
Usage data