Document Detail


Separating In vivo mechanical stimuli for postpneumonectomy compensation: Imaging and ultrastructural assessment.
MedLine Citation:
PMID:  23329819     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Following right pneumonectomy (PNX), the remaining lung expands and its perfusion more than doubles. Tissue and microvascular mechanical stresses are putative stimuli for compensatory lung growth and remodeling, but their relative contribution remains uncertain. To temporally separate expansion- and perfusion-related stimuli, we replaced the right lung of adult dogs with a customized inflated prosthesis. Four months later, the prosthesis was either acutely deflated (DEF) or kept inflated (INF). Thoracic high-resolution computed tomography (HRCT) was performed pre- and post-PNX before and after prosthesis deflation. Lungs were fixed for morphometric analysis ~12mo post-PNX. The INF prosthesis prevented mediastinal shift and lateral lung expansion while allowing the remaining lung to expand 27-38% via caudal elongation, associated with reversible capillary congestion in dependent regions at low inflation and 40-60% increases in the volumes of alveolar sepal cells, matrix and fibers. Delayed prosthesis deflation led to further significant increases in lung volume, alveolar tissue volumes, and alveolar-capillary surface areas. At postmortem, alveolar tissue volumes were 33% higher in the DEF than the INF group. Lateral expansion explains ~65% of the total post-PNX increase in left lung volume assessed in vivo or ex vivo, ~36% of the increase in HRCT-derived (tissue+microvascular blood) volume, ~45% of the increase in ex vivo sepal extravascular tissue volume, and 60% of the increase in gas exchange surface areas. This partition agrees with independent physiological measurements obtained in these animals. We conclude that in vivo signals related to lung expansion and perfusion contribute separately and nearly equally to post-PNX growth and remodeling.
Authors:
Priya Ravikumar; Cuneyt Yilmaz; Dennis J Bellotto; D Merrill Dane; Aaron S Estrera; Connie C W Hsia
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Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-1-17
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  -     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2013 Jan 
Date Detail:
Created Date:  2013-1-18     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
1University of Texas Southwestern Medical Center at Dallas.
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