Impaired angiotensin conversion and bradykinin clearance in experimental canine pulmonary emphysema

Details

Serval ID
serval:BIB_B2A74A383C55
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Impaired angiotensin conversion and bradykinin clearance in experimental canine pulmonary emphysema
Journal
Journal of Clinical Investigation
Author(s)
Stalcup  S. A., Leuenberger  P. J., Lipset  J. S., Osman  M. M., Cerreta  J. M., Mellins  R. B., Turino  G. M.
ISSN
0021-9738 (Print)
Publication state
Published
Issued date
01/1981
Volume
67
Number
1
Pages
201-9
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Jan
Abstract
Chronic hypoxic lung diseases are associated with abnormal blood pressure regulation. Because the lung is the principal site of angiotensin conversion and because hypoxia decreases converting enzyme activity, we examined whether angiotensin converting enzyme activity was impaired in lung disease. 12 dogs received a 6 wk course of aerosolized and intratracheal papain that produced moderate panlobular emphysema. These dogs and 24 control dogs were anesthetized and sampling catheters were placed under fluoroscopic control. Angiotensin conversion was measured by a blood pressure response bioassay. Pulmonary converting enzyme activity was also assessed by infusing bradykinin (BK) and using radioimmunoassay to measure the instantaneous clearance of BK and the concentration of BK in the pulmonary artery which first produced spillover of BK into left atrial blood. Angiotensin conversion was reduced in the emphysematous dogs to 81.1% (13.2 SD) from 92% (6 SD) in the control dogs (P < 0.01). Instantaneous clearance of BK in the emphysematous dogs was only slightly reduced (93%), despite reduction in their Pao(2) to 75 mm Hg, indicating that the greatest proportion of the perfused vascular bed was exposed to alveolar Po(2) of >90 mm Hg. However, the barrier to BK passage provided by the lung, and measured by the spillover level, was reduced (1/4) to (1/2) that observed in control animals. That the defect was promptly corrected by supplemental oxygen indicates that regional pulmonary vascular converting enzyme activity had been impaired by regional alveolar hypoxia, which permitted some peptide to pass through the lungs unmetabolized. Determination of peptide metabolism in the lungs may provide a useful measure of regional alveolar hypoxia and may lead to new ways of assessing lung injury.
Keywords
Angiotensin I/blood Animals Blood Pressure Bradykinin/*blood Dogs Lung/*blood supply/pathology Oxygen/physiology Peptidyl-Dipeptidase A/*blood Pulmonary Emphysema/blood/*enzymology/pathology
Pubmed
Web of science
Open Access
Yes
Create date
25/01/2008 9:49
Last modification date
20/08/2019 15:21
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