| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Pediatrics and Neonatal Perinatal Research Institute, Duke University Medical Center, Durham, NC, USA
* To whom correspondence should be addressed. E-mail: lu.wang{at}duke.edu.
Deep inspiration counteracts bronchospasm in normal subjects but triggers further bronchoconstriction in hyperresponsive airways. Although the exact mechanisms for this contrary response by normal and hyperresponsive airways are unclear, it has been suggested that the phenomenon is related to changes in force generating ability of airway smooth muscle after mechanical oscillation. It is known that healthy immature airways of both human and animal exhibit hyperresponsiveness. We hypothesize that the profile of active force generation after mechanical oscillation changes with maturation and that this change contributes to the expression of airway hyperresponsiveness in juveniles. We examined the effect of an acute sinusoidal length oscillation on the force generating ability of tracheal smooth muscle from 1 week, 3 week, and 2-3 month-old guinea pigs. We found that the length oscillation produced 15-20% initial reduction in active force equally in all age groups. This was followed by a force recovery profile that displayed striking maturation-specific features. Unique to tracheal strips from 1wk animals, active force potentiated beyond the maximal force generated before oscillation. We also found that actin polymerization was required in force recovery and that prostanoids contributed to the maturation-specific force potentiation in immature airway smooth muscle. Our results suggest a potentiated mechano-sensitive contractile property of hyperresponsive airway smooth muscle. This can account for further bronchoconstriction triggered by deep inspiration in hyperresponsive airways.
This article has been cited by other articles:
|
|
 |
|
  X. Tang and K. T. Chong Histopathology and growth kinetics of influenza viruses (H1N1 and H3N2) in the upper and lower airways of guinea pigs J. Gen. Virol., February 1, 2009; 90(2): 386 - 391. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Wang, V. Pozzato, G. Turato, A. Madamanchi, T. M. Murphy, and P. Chitano Reduced spontaneous relaxation in immature guinea pig airway smooth muscle is associated with increased prostanoid release Am J Physiol Lung Cell Mol Physiol, May 1, 2008; 294(5): L964 - L973. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. S. An, T. R. Bai, J. H. T. Bates, J. L. Black, R. H. Brown, V. Brusasco, P. Chitano, L. Deng, M. Dowell, D. H. Eidelman, et al. Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma Eur. Respir. J., May 1, 2007; 29(5): 834 - 860. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. E. Ford and S. H. Gilbert The importance of maturational studies in airway smooth muscle Am J Physiol Lung Cell Mol Physiol, December 1, 2005; 289(6): L898 - L901. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
