Acetamide-45 inhibits histamine-and methacholine-induced contraction of isolated guinea pig trachea.
OBJECTIVE
To investigate the effects of the new antiallergic agent N-(pyridin-4-yl)-(indol-3-yl) acetamide-45 (acetamide-45) on histamine- and methacholine-induced contraction of the isolated guinea pig trachea.


METHODS
Cumulative histamine or methacholine concentration-contraction studies were carried out in the absence or presence of acetamide-45. Changes in isometric force were measured by force transducers and recorded on a multi-channel polygraph recorder.


RESULTS
Acetamide-45 (1 - 30 micromol/L) concentration-dependently inhibited histamine- or methacholine-induced contractile response of isolated guinea pig trachea. At concentrations of 3, 10, 30 mumol/L, acetamide-45 significantly decreased maximum contractile response to histamine by 21 % - 51 %, and EC50 values (95 % confidence limits) were 31.1 (24.4 - 39.8), 34.7(26.8 - 45.0), and 134.4 (82.2 - 220.0) micromol/L, respectively. Similarly, acetamide-45 also inhibited the contraction induced by methacholine in isolated guinea pig trachea.


CONCLUSIONS
Acetamide-45 inhibited histamine- or methacholine-induced contraction of isolated guinea pig trachea, and these effects might be non-specific for either histamine receptor or cholinoceptor.
Lu
Yun-Bi
YB
Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310031, China. chenzfl@hotmail.com
Chen
Zhong
Z
Wu
Ming
M
D000818:Animals; D018926:Anti-Allergic Agents / Q000494:pharmacology*; D016085:Bronchoconstrictor Agents / Q000494:pharmacology*; D004347:Drug Interactions; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D053284:Polyunsaturated Alkamides; D011725:Pyridines / Q000494:pharmacology*; D014132:Trachea / Q000502:physiology*
D018926:Anti-Allergic Agents; D016085:Bronchoconstrictor Agents; D007210:Indoleacetic Acids; C117659:N-(pyridin-4-yl)-(1-(4-fluorobenzyl)indol-3-yl)acetamide; D053284:Polyunsaturated Alkamides; D011725:Pyridines; D016210:Methacholine Chloride; D006632:Histamine