Localization of cholinergic nerves in the lower airways of the
guinea pig using antisera to choline acetyltransferase.
Canning, Brendan J., and Axel Fischer.
The Johns Hopkins Asthma & Allergy Center, 5501 Hopkins Bayview
Circle, Baltimore, MD 21224 USA (BJC) and Institute for Anatomy and
Cell Biology, Justus-Liebig-University Giessen, Germany (AF)
APStracts 3:0233L, 1996.
Primary antiserum to choline acetyltransferase (ChAT), a specific
marker for cholinergic nerves, was utilized to characterize the
distribution of cholinergic nerve fibers and nerve cell bodies in
guinea pig airways. ChAT immunoreactive nerve fibers were localized
to the smooth muscle throughout the conducting airways and in the
lamina propria of the trachea and large bronchi. Likewise, all nerve
cell bodies in the ganglia intrinsic to the trachea and bronchi
displayed a cholinergic phenotype. By contrast, ChAT immunoreactive
nerve fibers were infrequently seen in the lamina propria of the
peripheral airways and absent in the airway epithelium. No evidence
for colocalization of ChAT and the enzyme synthesizing the putative
relaxant neurotransmitter nitric oxide (NO synthase) was observed.
These results provide further evidence for the key role played by
cholinergic nerves in regulating airway smooth muscle tone and
bronchial blood flow and provide further evidence that acetylcholine
is not coreleased with the neurotransmitter(s) mediating relaxations
of airway smooth muscle.
Received 11 September 1995; accepted in final form 15 November
1996.
APS Manuscript Number L273-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996