Anticholinesterase drugs stimulate smooth muscle contraction of the rat trachea through the Rho-kinase pathway.
We performed this study to determine the effects of Rho-kinase inhibitors, Y-27632 and fasudil, on the anticholinesterase (anti-ChE)-induced contractile and phosphatidylinositol responses of the rat trachea. In vitro measurements of isometric tension and [3H] inositol monophosphate (IP1) that was formed were conducted by using rat tracheal rings or slices. Neostigmine- and pyridostigmine-induced contractions were almost completely inhibited by Y-27632 and fasudil at 30 microM each, whereas acetylcholine-induced contraction was inhibited incompletely, i.e., by 56% by Y-27632 and by 51% by fasudil, at 100 microM for each, respectively. The inhibitory effects of fasudil on neostigmine- and acetylcholine-induced contractions were completely reversed by calyculin-A, a myosin phosphatase inhibitor. Neostigmine-induced IP1 accumulation was attenuated by fasudil at 100 microM. The results suggest that anti-ChEs cause airway smooth muscle contraction, in part, through activation of the Rho-kinase pathway.
Shibata
Osamu
O
Department of Anesthesiology, Nagasaki University School of Medicine, Nagasaki, Japan. opshiba@net.nagasaki-u.ac.jp
Saito
Masataka
M
Yoshimura
Maki
M
Yamaguchi
Masakazu
M
Nishioka
Kenji
K
Makita
Tetsuji
T
Sumikawa
Koji
K
D000818:Animals; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects* / Q000201:enzymology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014132:Trachea / Q000187:drug effects* / Q000201:enzymology; D054460:rho-Associated Kinases
D002800:Cholinesterase Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D047428:Protein Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases