Effect of cooling on the responsiveness of canine tracheal muscle.

Published

Journal Article

Airway cooling causes bronchoconstriction in many persons who have asthma. To determine the direct effect of cooling on the response of tracheal muscle to parasympathetic and muscarinic stimuli in situ, the temperature of a segment of canine cervical trachea was adjusted to 37 degrees, 30 degrees, or 25 degrees C by superfusing temperature-controlled saline over its epithelial surface. The contractile response of the tracheal muscle to electrical stimulation of the vagus nerves and to intra-arterial acetylcholine was then determined. Cooling the segment to 25 degrees C decreased the contraction induced by parasympathetic stimulation. However, cooling did not alter the contraction induced by intra-arterial acetylcholine. Parallel studies were conducted in vitro using nine excised tracheal muscle strips taken from the same section of trachea in three additional dogs. Cooling the tracheal muscle to 25 degrees C in vitro increased the maximal contraction induced by both electrical field stimulation and by acetylcholine. Thus, cooling in situ does not alter the response of tracheal muscle to muscarinic stimuli and inhibits the response to parasympathetic stimuli. These data indicate that augmentation of the tracheal muscle response elicited by cooling in vitro does not reflect the response in situ. They suggest that a direct effect of cooling on airway smooth muscle response to parasympathetic and muscarinic stimuli does not account for cooling-induced bronchoconstriction in vivo.

Full Text

Duke Authors

Cited Authors

  • Bethel, RA; Tanaka, DT; Mitchell, LS; Curtis, SP; Leff, AR; Irvin, CG

Published Date

  • December 1990

Published In

Volume / Issue

  • 142 / 6 Pt 1

Start / End Page

  • 1402 - 1406

PubMed ID

  • 2252259

Pubmed Central ID

  • 2252259

International Standard Serial Number (ISSN)

  • 0003-0805

Digital Object Identifier (DOI)

  • 10.1164/ajrccm/142.6_Pt_1.1402

Language

  • eng

Conference Location

  • United States