The effect of pancuronium and vecuronium on isolated tracheal smooth muscle of the guinea pig
Mihara, J.
Masui. Japanese Journal of Anesthesiology 35(12): 1866-1873
1986
ISSN/ISBN: 0021-4892 PMID: 2882034 Document Number: 273310
The effect of pancuronium bromide (PB) and vecuronium bromide (VB) on the isometric contraction of tracheal smooth muscle induced by acetycholine (ACh), carbachol (CCh) and electrical stimulation was studied using the isolated tracheal stripchain preparation of guinea pig. The preparation was suspended in a 30 ml organ bath with modified Krebs-Ringer solution are with 5%CO2 in oxygen at 37.degree. C, and pretreated with guanethidine (10-6 M) and indomethacin (2 .times. 10P-6M). Electrical stimulation was of 8 Hz in frequency, 40 pulse and supramaximal voltage. The dose-response curve to ACh and CCh was obtained applying the cumulative dose technique. The electrically induced contraction was enhanced in presence of Pb (10-6, 3 .times. 10-6 M) and VB (10-6 .apprx. 3 .times. 10-5M) in a dose-dependent manner, but reduce by PB of relatively high concentration (3 .times. 10-5M). The ACh dose-response curve (10-7 .apprx. 3 .times. 10-6 M) was shifted to the right by pretreatment with PB (10-6, 10-5 M), but on the contrary, shifted to the left by VB (10-6, 10-5M). The curve of CCh (10-8 .apprx. 3 .times. 10-6M) which is resistant to hydrolysis by acetylcholinesterase, was shifted to the right by Pb as in the ACh curve but unaffected or slighty shifted to the right by VB. These results suggest that the atropine-like action of PB and the antiacetylcholinesterase one of VB are elucidated on the tracheal smooth muscle of guinea pig.