Airway basement membrane perimeter distensibility and airway smooth muscle area in asthma

• Published in: Journal of applied physiology (1985) 2008-06, Vol.104 (6), p.1703-1708
• Main Authors: James, Alan L, Green, Francis H, Abramson, Michael J, Bai, Tony R, Dolhnikoff, Marisa, Mauad, Thais, McKay, Karen O, Elliot, John G
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Airway management; Asthma; Asthma - mortality; Asthma - pathology; Asthma - physiopathology; Australia; Basement Membrane - pathology; Basement Membrane - physiopathology; Biological and medical sciences; Brazil; British Columbia; Case-Control Studies; Child; Comparative analysis; Effects; Female; Fundamental and applied biological sciences. Psychology; Humans; Lung - pathology; Lung - physiopathology; Lung Compliance; Lungs; Male; Membranes; Middle Aged; Muscle, Smooth - pathology; Muscle, Smooth - physiopathology; New Zealand; Tissues
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00169.2008

1 Department of Pulmonary Physiology, West Australian Sleep Disorders Research Institute, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia; 2 School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia; 3 University of Calgary, Calgary, Alberta, Canada; 4 Department of Epidemiology and Preventive Medicine, Monash University, Victoria, Australia; 5 University of British Columbia, Vancouver, British Columbia, Canada; 6 University Medical School, São Paulo, São Paulo, Brazil; and 7 Children's Hospital at Westmead, Sydney, New South Wales, Australia Submitted 13 February 2008 ; accepted in final form 26 March 2008 The perimeter of the basement membrane (Pbm) of an airway viewed in cross section is used as a marker of airway size because in normal lungs it is relatively constant, despite variations in airway smooth muscle (ASM) shortening and airway collapse. In vitro studies (McParland BE, Pare PD, Johnson PR, Armour CL, Black JL. J Appl Physiol 97: 556-563, 2004; Noble PB, Sharma A, McFawn PK, Mitchell HW. J Appl Physiol 99: 2061-2066, 2005) have suggested that differential stretch of the Pbm between asthmatic and nonasthmatic airways fixed in inflation may occur and lead to an overestimation of ASM thickness in asthma. The relationships between the Pbm and the area of ASM were compared in transverse sections of airways from cases of fatal asthma (F) and from nonasthmatic control (C) cases where the lung tissue had been fixed inflated (Fi; Ci) or uninflated (Fu; Cu). When all available airways were used, the regression slopes were increased in Fu and Cu, compared with Fi and Ci, and increased in Fu and Fi, compared with Cu and Ci, suggesting effects of both inflation and asthma group, respectively. When analyses were limited to airway sizes that were available for all groups (Pbm < 15 mm), the slopes of Fi and Fu were similar, but both were greater than Ci and Cu, which were also similar. It was calculated that the effect of asthma group accounted for 80% and inflation for 20% of the differences between Fi and Ci. We conclude that the effects of inflation on the relationship between Pbm and ASM are small and do not account for the differences observed in ASM between cases of asthma and nonasthmatic controls. lung inflation Address for reprint requests and other correspondence: A. L. James, West Australian Sleep Disorders Research Institute, Internal Mailbox 201, Queen Elizabeth II Medical Cen