Journal of Applied Physiology, Vol 63, Issue 1 434-439, Copyright © 1987 by American Physiological Society
Immunohistochemical identification of lung cells responsive to beta-stimulation with a rise in cAMP
T. B. Casale, D. Wood, S. Wescott and M. Kaliner
To identify specific lung cells possessing functional beta-adrenergic
receptors, we developed an immunoperoxidase-staining procedure capable of
in situ localization of cells responding to beta-agonist stimulation with a
rise in adenosine 3',5'-cyclic monophosphate (cAMP). Isoproterenol was
instilled into the airways of excised intact guinea pig lungs for 5 min and
resulted in a six to eightfold rise in cAMP. Immediately thereafter, the
lungs were washed in and fixed with 10% buffered Formalin. Sections were
then stained using immunoperoxidase techniques and monoclonal antibodies
directed against cAMP. We found that isoproterenol-stimulated lungs had
widespread increased staining for immunoreactive cAMP. The specific cells
consistently demonstrating marked increases in staining were airway
epithelial cells, airway smooth muscle cells, alveolar and parenchymal
macrophages, and alveolar lining cells, including both type I and type II
cells, and capillary endothelial cells. Of all tissues, the airway
epithelium was the most intensely stained area for beta-agonist-induced
immunoreactive cAMP. The techniques employed herein should make possible
the in situ localization of cells responding to any stimuli capable of
increasing cAMP, thereby allowing the specific identification of cells
possessing functional adenylate cyclase-linked receptors.
