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Bronchial responsiveness among inbred mouse strains. Role of airway smooth-muscle shortening velocity
- Source :
- American journal of respiratory and critical care medicine. 161(3 Pt 1)
- Publication Year :
- 2000
-
Abstract
- To investigate the relationship between bronchial responsiveness and airway smooth-muscle (ASM) contractile properties, we studied inbred mice with known interstrain differences in airway responsiveness. Using oscillatory mechanics, we confirmed that A/J mice were hyperresponsive to methacholine (MCh) as compared with mice of the C3H/HeJ and C57BL/6J strains. Analysis of respiratory system resistance and elastance at different flow oscillation frequencies indicated that interstrain differences in responsiveness are present in both central and peripheral airways of these mice. We used video microscopy to measure the rate of contraction of explanted airways, and found that the airways of A/J mice contracted more rapidly than those of C3H/HeJ or C57BL/6J mice. In studies of a fourth strain (Balb/C) of mice, we found both bronchial hyperresponsiveness and increased ASM shortening velocity. The rank order of responsiveness among strains was the same as that for shortening velocity (A/J > Balb/C > C3H/HeJ > C57BL/6J). Furthermore, in each strain of mice, shortening velocity correlated with the achieved degree of airway narrowing and with a greater likelihood of airway closure in individual airways. In contrast, generation of isometric tension in trachealis, morphometric measurements of tracheal ASM, tracheal myosin content, and dose-response curves for MCh of explanted intraparenchymal bronchi failed to correspond to the in vivo phenotype of airway reactivity. These results indicate that bronchial responsiveness is related to ASM shortening velocity, and underscore the importance of smooth-muscle dynamics in understanding the mechanisms of bronchial responsiveness.
- Subjects :
- Pulmonary and Respiratory Medicine
Male
Pathology
medicine.medical_specialty
Genotype
Video microscopy
Bronchi
Isometric exercise
Critical Care and Intensive Care Medicine
Bronchial Provocation Tests
Mice
Species Specificity
medicine
Animals
Respiratory system
Methacholine Chloride
Bronchus
business.industry
Airway Resistance
Muscle, Smooth
respiratory system
medicine.disease
respiratory tract diseases
medicine.anatomical_structure
Bronchial hyperresponsiveness
Trachealis muscle
Methacholine
Bronchial Hyperreactivity
business
Airway
medicine.drug
Subjects
Details
- ISSN :
- 1073449X
- Volume :
- 161
- Issue :
- 3 Pt 1
- Database :
- OpenAIRE
- Journal :
- American journal of respiratory and critical care medicine
- Accession number :
- edsair.doi.dedup.....ad914ad5538d3f3798a3383797bd83d6