Workshop on airway smooth muscle. Summary of a conference held September 25-27 1983.

Abstract

Airway smooth muscle contraction and the extreme sensitivity of the airway smooth muscle responses to various stimuli are accepted as key factors in the pathogenesis of asthma and are recognized to be important in other diseases (e.g., bronchitis and cystic fibrosis). A Workshop on Airway Smooth Muscle sponsored by the National Heart, Lung and Blood Institute (September 25 to 27, 1983) identified various avenues of future research. Smooth muscle anatomists pointed to the paucity of quantitative information on airway smooth muscle structure, especially electron microscopic information and details of the neural arrangement. Investigations of the neural network, similar to those that have led to important discoveries in the gut, are urgently needed. Now that intramural ganglia can be studied electrophysiologically (and in vivo!), new information concerning possible local neural modulation can be examined. A similar lack of information was found in the biochemical study of airway smooth muscle. Among potential causes of abnormalities in asthmatic muscles are alterations in membrane channels and pumps, receptor transduction processes, cGMP-mediated processes, and other metabolic pathways. Inflammation and inflammatory mediators appear to play important roles in disease of airway smooth muscle. Utilization of cell isolation and culture, and immunologic and other cell biologic and biochemical methods will accelerate the study of the various cells in the airways, their interactions, and their roles in disease. Of special potential importance are peptide and lipid mediators produced by various airway cells. Development of synthetic analogues and antagonists, including monoclonal antibodies, will provide more specific tools for dissecting these cell-to-cell interactions. Regardless of the level of study--from examination of the whole organism to molecular mechanisms--the fact is that there is no entirely satisfactory animal "model" of asthma or asthmatic muscle, presumably because we do not fully understand the etiology and pathogenesis of asthma. This makes it all the more important to take appropriate opportunities to obtain tissue from asthmatics for laboratory study. Relatively simple, careful studies of asthmatic smooth muscle may prove important, unique insights into its possible abnormalities.