[Inhibition of acetamide-45 on airway smooth muscle contraction induced by electric field stimulation and methacholine in vitro].
To investigate the effects of the new antiallergic agent N-(pyridin-4-yl)-(indol-3-yl) acetamide-45 (acetamide-45) on electric field stimulation (EFS)-and methacholine-induced contraction of airway smooth muscle in vitro.



Contractions were induced by EFS in isolated trachea and bronchus of rats or by cumulative methacholine concentrations in isolated trachea of guinea pigs. Changes in isometric force of isolated airway smooth muscle were measured by force transducers and recorded on a multi-channel polygraph recorder.



Acetamide-45 inhibited the contraction induced by EFS in isolated rat airway. The IC50 was 10.74 (95% CI 8.87-13.00) micromol.L(-1) and 18.83 (95% CI 14.57-24.33) micromol.L(-1) in tracheae and bronchi, respectively. Acetamide-45 also inhibited methacholine-induced contractile response of isolated guinea pig trachea in a concentration-dependent manner. At concentrations of 3, 10, 30 micromol.L(-1) acetamide-45 significantly decreased maximal contractile response of methacholine by 24.6%-43.2% and increased EC50 of methacholine by 3.1-to 21.4-fold.



Acetamide-45 inhibits EFS-or methacholine-induced contraction of isolated airway smooth muscle, and these effects might be non-specific inhibition on cholinergic receptor.
Lu
Yun-bi
YB
College of Medicine, Zhejiang University, Hangzhou 310031, China.
Chen
Zhong
Z
Lai
Xiao-yu
XY
Gao
Yun
Y
D000081:Acetamides / Q000494:pharmacology*; D000818:Animals; D003864:Depression, Chemical; D004558:Electric Stimulation; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014132:Trachea / Q000187:drug effects
D000081:Acetamides; D016210:Methacholine Chloride; C030686:acetamide