Journal of Applied Physiology Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 63: 2008-2014, 1987;
8750-7587/87 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Murphy, T. M.
Right arrow Articles by Leff, A. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Murphy, T. M.
Right arrow Articles by Leff, A. R.

Journal of Applied Physiology, Vol 63, Issue 5 2008-2014, Copyright © 1987 by American Physiological Society

ARTICLES

Mechanisms of airway hypercontractility in basenji-greyhound dogs

T. M. Murphy, N. M. Munoz, C. A. Hirshman, J. S. Blake and A. R. Leff
Department of Pediatrics, University of Chicago, Illinois 60637.

The comparative effects of contractile agonists and physiological stimulation of the tracheal and bronchial smooth muscle (BSM) response were studied isometrically in situ in five Basenji-greyhound (BG) and six mongrel dogs. Frequency-response curves generated by bilateral stimulation of the vagus nerves (0-20 Hz, 15-20 V, 2-ms duration) elicited greater maximal contraction in mongrel trachea (36.8 +/- 8.1 vs. 26.9 +/- 4.0 g/cm; P less than 0.02) and exhibited greater responsiveness in mongrel BSM (half-maximal response to electrical stimulation 3.0 +/- 1.1 vs. 7.0 +/- 0.5 Hz; P less than 0.05) compared with BG dogs. However, muscarinic sensitivity to intravenous methacholine (MCh) was substantially greater in BG dogs; MCh caused contraction greater than 1.5 g/cm at a mean dose of 3.0 X 10(-10) mol/kg for BG dogs compared with 5.1 X 10(-9) mol/kg for mongrel controls (P less than 0.03, Mann-Whitney rank-sum test). In contrast to the muscarinic response, the contractile response elicited by intravenous norepinephrine after beta-adrenergic blockade was similar in trachea and bronchus for both mongrel and BG dogs. Our data confirm previous in vitro demonstration of tracheal hyporesponsiveness in BG dogs and demonstrate that the contraction resulting from efferent parasympathetic stimulation is less in the BG than mongrel dogs. However, postsynaptic muscarinic responsiveness of BG BSM is substantially increased. We conclude that a component of airway responsiveness in BG dogs depends directly on contractile forces generated postsynaptically that are nongeometry dependent, postjunctional, and agonist specific.


This article has been cited by other articles:


Home page
 Proc Am Thorac SocHome page
J. G. Martin and T. Jo
Genetic Differences in Airway Smooth Muscle Function
Proceedings of the ATS, January 1, 2008; 5(1): 73 - 79.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online