Muscarinic and [beta]-adrenergic receptor expression in peripheral
lung from normal and asthmatic patients.
Haddad, El-Bdaoui, Judith C. W. Mak, Maria G. Belvisi, Masanori
Nishikawa, Jonathan Rousell, and Peter J. Barnes.
Department of Thoracic Medicine, National Heart & Lung
Institute, London, U.K.
APStracts 3:0015L, 1996.
We used human peripheral lung from 8 mild asthmatic patients and 11
normal donors in order to study the expression of muscarinic and
[beta]-adrenergic receptors in asthma. There was a no significant
difference in the affinity or the density of muscarinic (labelled
with [N-methyl-3H]scopolamine) and [beta]1- and [beta]2-adrenergic
receptors (labelled with [125I]iodocyanopindolol) in peripheral lung
from asthmatics compared to nonasthmatics. Only the muscarinic m1
receptor mRNA was detected in human lung using Northern blot
analysis. Additionally, peripheral lung cellular mRNA hybridized to
human [beta]1 and [beta]2 cDNA probes giving 3.2 and 2.2 kb bands
corresponding to [beta]1 and [beta]2-adrenoceptors mRNA respectively.
Densitometric scanning of the autoradiograms suggests that there was
no significant difference in the relative abundance of muscarinic m1
and [beta]1- and [beta]2-adrenergic receptor mRNAs in asthmatic
compared to nonasthmatic lungs. Functional experiments obtained in
trachea suggest that there was an increase in the cholinergic neural
response evoked by EFS in asthmatic compared to nonasthmatic tissues
which was not due to a reduction in inhibitory noncholinergic
nonadrenergic (iNANC) relaxations.
Received 20 June 1995; accepted in final form 5 January 1996.
APS Manuscript Number L193-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 January 96