RT Journal Article
SR Electronic
T1 Mechanical properties of asthmatic airway smooth muscle
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 45
OP 54
DO 10.1183/09031936.00065411
VO 40
IS 1
A1 Leslie Y.M. Chin
A1 Ynuk Bossé
A1 Chris Pascoe
A1 Tillie L. Hackett
A1 Chun Y. Seow
A1 Peter D. Paré
YR 2012
UL http://erj.ersjournals.com/content/40/1/45.abstract
AB Airway smooth muscle (ASM) is the major effector of excessive airway narrowing in asthma. Changes in some of the mechanical properties of ASM could contribute to excessive narrowing and have not been systematically studied in human ASM from nonasthmatic and asthmatic subjects. Human ASM strips (eight asthmatic and six nonasthmatic) were studied at in situ length and force was normalised to maximal force induced by electric field stimulation (EFS). Measurements included: passive and active force versus length before and after length adaptation, the force–velocity relationship, maximal shortening and force recovery after length oscillation. Force was converted to stress by dividing by cross-sectional area of muscle. The only functional differences were that the asthmatic tissue was stiffer at longer lengths (p<0.05) and oscillatory strain reduced isometric force in response to EFS by 19% as opposed to 36% in nonasthmatics (p<0.01). The mechanical properties of human ASM from asthmatic and nonasthmatic subjects are comparable except for increased passive stiffness and attenuated decline in force generation after an oscillatory perturbation. These data may relate to reduced bronchodilation induced by a deep inspiration in asthmatic subjects.