Abstract
Two morphometric indices, the destructive index (DI), a measure of alveolar wall destruction, and the proportion of destroyed alveolar attachments to the airways (AA), have been proposed as measures of early lung destruction in human smokers. The aim of this study was to compare DI and AA to the usual measure of airspace enlargement--the mean linear intercept (Lm)--in experimental emphysema. Porcine pancreatic elastase was administered intratracheally to 2 groups of Brown Norway rats (high-dose, n = 8, 1 IU/g body weight; low-dose, n = 4, 0.7 IU/g; control, n = 7). Total lung capacity (TLC), functional residual capacity (FRC) and pressure-volume curves were measured 3 weeks after administration of elastase. Lung elasticity was assessed by chord compliance (Cst). Administration of high-dose, but not low-dose, elastase led to significant increases in FRC and TLC. Cst significantly increased after high-dose elastase compared to controls (p less than 0.01). Lm increased after both low-dose and high-dose elastase compared to controls (p less than 0.01); DI and AA were increased only after high-dose elastase. Significant correlations were found between each morphometric index and Cst; the highest correlation was with AA. Behavior of the morphometric indices in this model differed from that reported in human smokers: Lm was a more sensitive measure of destruction than DI, reflecting a process marked by predominance of airspace enlargement over alveolar septal breaks. These differences from human smokers may result from a differing underlying pathogenesis of lung destruction.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.