Journal of Applied Physiology, Vol 71, Issue 3 886-891, Copyright © 1991 by American Physiological Society

ARTICLES

Partitioning of pulmonary responses to inhaled methacholine in puppies

P. D. Sly and C. J. Lanteri
Clinical Science Division, Western Australian Research Institute for Child Health, Perth.

Twelve open-chest mongrel puppies, 8-10 wk old, were studied to localize the site of action of inhaled methacholine within the lungs. Six puppies were challenged with methacholine aerosols and six were challenged with an equal number of nebulizations of normal saline (control group). Pulmonary mechanics were measured during mechanical ventilation and after midexpiratory flow interruptions. Alveolar pressure was measured to allow the partitioning of pulmonary mechanics into airway and tissue components. Good matching between airway opening and alveolar pressures was seen throughout the study. After methacholine challenge, lung resistance increased fivefold. Increases in airway resistance and in the parameters reflecting tissue viscoelastic properties contributed to this increase in lung resistance. Dynamic lung elastance also increased threefold. The response of the methacholine group was statistically different from that of the control group. These data indicate that both the airways and pulmonary parenchyma contribute to the response to inhaled methacholine in 8- to 10-wk-old puppies.

This article has been cited by other articles:

				P D Sly and E Lombardi Measurement of lung function in preschool children using the interrupter technique Thorax, September 1, 2003; 58(9): 742 - 744. [Full Text] [PDF]

				G L Hall, Z Hantos, J H Wildhaber, F Peták, and P D Sly Methacholine responsiveness in infants assessed with low frequency forced oscillation and forced expiration techniques Thorax, January 1, 2001; 56(1): 42 - 47. [Abstract] [Full Text]

				T. UHLIG, J. H. WILDHABER, N. CARROLL, D. J. TURNER, P. R. GRAY, N. DORE, A. L. JAMES, and P. D. SLY Pulmonary Vascular Congestion Selectively Potentiates Airway Responsiveness in Piglets Am. J. Respir. Crit. Care Med., April 1, 2000; 161(4): 1306 - 1313. [Abstract] [Full Text]

				F. Petak, J. L. Wale, and P. D. Sly Effects of salbutamol and Ro-20-1724 on airway and parenchymal mechanics in rats J Appl Physiol, October 1, 1999; 87(4): 1373 - 1380. [Abstract] [Full Text] [PDF]

				J L Wale, F Peták, and P D Sly Muscarinic blockade of methacholine induced airway and parenchymal lung responses in anaesthetised rats Thorax, June 1, 1999; 54(6): 531 - 537. [Abstract] [Full Text]

				F. Petak, G. L. Hall, and P. D. Sly Repeated measurements of airway and parenchymal mechanics in rats by using low-frequency oscillations J Appl Physiol, May 1, 1998; 84(5): 1680 - 1686. [Abstract] [Full Text] [PDF]

				F. Petak, Z. Hantos, A. Adamicza, T. Asztalos, and P. D. Sly Methacholine-induced bronchoconstriction in rats: effects of intravenous vs. aerosol delivery J Appl Physiol, May 1, 1997; 82(5): 1479 - 1487. [Abstract] [Full Text] [PDF]