Document Detail


Alterations in structure of elastic laminae of rat pulmonary arteries in hypoxic hypertension.
MedLine Citation:
PMID:  8941540     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of hypoxic hypertension on the remodeling process of the elastic laminae of the rat hilar pulmonary arteries (PAs) was studied by electron microscopy. Rats were exposed to hypoxia (10% O2) for periods of 0.5, 2,6,12,48,96,144, and 240 h. Changes in the structure of the PA elastic laminae were examined and analyzed with respect to changes in the PA wall tensile stress. The PA blood pressure increased rapidly within the first several hours of hypoxia and reached a stable level within 2 days, whereas the PA wall tensile stress increased initially due to elevated blood pressure and then decreased after 48 h due to vessel wall thickening and returned to the control level after 4 days. In association with these changes, the elastic laminae, which appeared homogeneous in normal control rats, changed into structures composed of randomly oriented filaments and edematous contents with an increase in the volume during the early period of hypoxia and regained their homogeneous appearance and normal volume after 4 days. The changes in the elastic laminae were correlated with changes in the tensile stress. These changes were associated with a transient decrease in the stiffness of the PAs. In hypoxic rats given nifedipine, no change was found in the blood pressure, the tensile stress, or the structure of the elastic laminae of the PAs despite continuous exposure to hypoxia. These results suggested that altered tensile stress in the PA wall played a critical role in the initiation and regulation of structural changes in the elastic laminae and that these changes might contribute to alterations in the mechanical properties of the PA in hypoxic hypertension.
Authors:
S Q Liu
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  81     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1996 Nov 
Date Detail:
Created Date:  1997-03-13     Completed Date:  1997-03-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2147-55     Citation Subset:  IM    
Affiliation:
Biomedical Engineering Department, Northwestern University, Evanston, Illinois 60208-3107, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia / pathology*
Calcium Channel Blockers / pharmacology
Cardiac Output / drug effects,  physiology
Elasticity
Hypertension / pathology*
Male
Microscopy, Electron
Nifedipine / pharmacology
Oxygen / blood
Pulmonary Artery / drug effects,  pathology*,  ultrastructure
Rats
Rats, Sprague-Dawley
Tensile Strength / drug effects,  physiology
Chemical
Reg. No./Substance:
0/Calcium Channel Blockers; 21829-25-4/Nifedipine; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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