Anesthesia & Analgesia, Vol 82, 1211-1214, Copyright © 1996 by International Anesthesia Research Society
Anticholinesterase drugs stimulate phosphatidylinositol response in rat tracheal slices
O Shibata, M Kanairo, S Zhang, H Hasuo, H Morooka, T Fujie and K Sumikawa
Department of Anesthesiology, Nagasaki University School of Medicine, Japan.
Some anticholinesterase (anti-ChE) drugs induce airway smooth muscle
contraction. Whether anti-ChE drugs stimulate muscarinic receptors in
airway smooth muscle as well as nicotinic receptors in neuromuscular
junction is unknown. Since there is a direct relationship between
phosphatidylinositol (PI) response and airway smooth muscle contraction
induced by muscarinic agonists, we examined the effects of neostigmine,
physostigmine, pyridostigmine, and edrophonium on PI response in the airway
smooth muscle. The rat tracheal slices were incubated in Krebs- Henseleit
solution containing LiCl and [3H]myo-inositol in the presence of carbachol,
anti-ChE, or none of them. [3H]inositol monophosphate (IP1), which is a
degradation product of PI response, was counted with a liquid scintillation
counter. Inositol monophosphate accumulation was stimulated by neostigmine,
physostigmine, and pyridostigmine in a dose- dependent manner, but was not
affected by edrophonium. These increases were completely inhibited by
atropine. The results suggest that neostigmine, physostigmine, and
pyridostigmine stimulate PI response in the airway smooth muscle, which
would cause bronchoconstriction, while edrophonium does not affect PI
response.
