[Neuromuscular blocking effect of ORG9426, a new non-depolarizing muscle relaxant, and its recovery with various antagonists in vitro].
We evaluated the neuromuscular blocking effect of ORG9426, a new non-depolarizing muscle relaxant, and its recovery by means of washout or by antagonists in vitro, using phrenic nerve-hemidiaphragm preparations of rats. IC50 and IC90 of ORG9426 in single twitch were 10.62 +/- 0.58 microM and 15.75 +/- 0.95 microM; and those in train of four ratio were 9.04 +/- 0.38 microM and 11.87 +/- 0.42 microM, respectively. The potency of ORG9426 in vitro was compared with those of other non-depolarizing muscle relaxants. The order of potency among the non-depolarizing muscle relaxants was the following: d-tubocurarine greater than pipecuronium greater than pancuronium greater than vecuronium greater than ORG9426. There was no difference between ORG9426 and vecuronium in the recovery from block with washout, neostigmine, 4-aminopyridine, 3, 4-diaminopyridine, and edrophonium. In conclusion, the potency of ORG9426 is relatively low, and it can be easily antagonized by anti-cholinesterases and aminopyridines.
Okamoto
T
T
Department of Anesthesiology, National Defense Medical College, Tokorozawa.
Aoki
T
T
Fukushima
K
K
Yoneda
I
I
Satoh
T
T
Nagashima
H
H
D000631:Aminopyridines / Q000494:pharmacology; D000732:Androstanols / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D003964:Diaphragm / Q000187:drug effects; D066298:In Vitro Techniques; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D010791:Phrenic Nerve / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077123:Rocuronium
D000631:Aminopyridines; D000732:Androstanols; D002800:Cholinesterase Inhibitors; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium