Premium
Effect of cromakalim on bronchoconstriction evoked by cholinergic nerve stimulation in guinea‐pig isolated trachea
Author(s) -
McCaig Dorothy J.,
Jonckheere B.
Publication year - 1989
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1989.tb12641.x
Subject(s) - cromakalim , bronchoconstriction , guinea pig , stimulation , cholinergic , medicine , cavia , anesthesia , vagus nerve , acetylcholine , pharmacology , agonist , airway , receptor
1 Cromakalim reduced intraluminal pressure in the guinea‐pig isolated, innervated trachea. 2 Preganglionic stimulation of the cervical vagus nerve elicited a frequency‐dependent increase in intraluminal pressure. Cromakalim attenuated responses to vagal stimulation in a concentration‐dependent manner at all frequencies tested. 3 Field stimulation caused a frequency‐dependent increase in intraluminal pressure mediated by muscarinic cholinoceptors. Cromakalim did not affect the amplitude of responses at any frequency of stimulation, even at high concentrations. 4 Acetylcholine, added to the Krebs solution bathing the adventitial surface of the trachea, evoked a concentration‐dependent increase in intraluminal pressure. The concentration‐effect curve for acetylcholine was unaltered in the presence of cromakalim. 5 It is concluded that cromakalim modulates cholinergic neuroeffector transmission in the trachea chiefly by a prejunctional mechanism. However, cromakalim probably does not interfere with acetylcholine release from postganglionic cholinergic neurones.