Journal of Applied Physiology Email Content Delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 71: 1434-1440, 1991;
8750-7587/91 $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 Yang, J. N.
Right arrow Articles by Hirshman, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yang, J. N.
Right arrow Articles by Hirshman, C.

Journal of Applied Physiology, Vol 71, Issue 4 1434-1440, Copyright © 1991 by American Physiological Society

ARTICLES

Role of the epithelium in airway smooth muscle responses to relaxant agonists

J. N. Yang, W. Mitzner and C. Hirshman
Department of Environmental Health Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.

We studied the role of the guinea pig tracheal epithelium in modulating tracheal smooth muscle responses to the relaxant agonists albuterol, sodium nitroprusside, and theophylline. We used an in vitro preparation that allowed separation of the fluids bathing the luminal (internal) and serosal (external) surfaces of the trachea, and bronchodilators were administered to either surface of carbachol-contracted tracheae. All three drugs produced dose-dependent relaxation. However, albuterol and nitroprusside were less potent (concentration that produced half-maximal effect increased by 100- and 32-fold, respectively) when given to the epithelial side with the epithelium intact compared with the epithelium denuded or compared with serosal administration with the epithelium intact. These differences were not observed for theophylline, where smooth muscle responses were independent of either the side of stimulation or of the presence or absence of the epithelium. Direct measurements of the diffusion of theophylline across the tracheal wall in the presence or absence of epithelium showed that after 5 h of incubation with a fixed luminal concentration of theophylline, only 1.7% had diffused across the tracheal wall with the epithelium intact. This increased to only approximately 3.3% when the epithelium was denuded. These results suggest that the epithelial is a relatively weak barrier for lipophilic agents but has a major role as a diffusion barrier to hydrophilic substances.


This article has been cited by other articles:


Home page
 Am. J. Respir. Crit. Care Med.Home page
D. SPINA
Epithelium Smooth Muscle Regulation and Interactions
Am. J. Respir. Crit. Care Med., November 1, 1998; 158(2007): S141 - S145.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
U. M. Wells, S. Duneclift, and J. G. Widdicombe
H2O2 increases sheep tracheal blood flow, permeability, and vascular response to luminal capsaicin
J Appl Physiol, February 1, 1997; 82(2): 621 - 631.
[Abstract] [Full Text] [PDF]


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