Relationships between block-of-twitch and train-of-four fade in the mouse phrenic nerve-diaphragm preparation.
The relationships between the block-of-twitch and train-of-four fade in the presence of nondepolarizing neuromuscular blocking drugs (d-tubocurarine, vecuronium and pancuronium) were examined in vitro by measuring the contractile tension from mouse phrenic nerve-diaphragm preparations. The slope of the block/fade relationship differed between onset of and recovery from neuromuscular block following single doses of d-tubocurarine, vecuronium or pancuronium. Decreasing the dose of d-tubocurarine or using a divided dose technique to accelerate onset (i.e., priming) increased the amount of fade for a given amount of block. In addition, the block/fade relationships for cumulative dosing and sequential dilution were the same when measurements were made at steady-state for several doses. It is concluded that the block/fade relationship in the mouse phrenic nerve-diaphragm preparation is variable, and is related to the time course of the neuromuscular block. In addition, the block/fade relationships for d-tubocurarine, vecuronium and pancuronium did not differ when determined at steady-state.
Department of Anesthesiology, Hahnemann University, Philadelphia, PA 19102.
R J
RJ
Storella
S A
SA
Slomowitz
H
H
Rosenberg
D000818:Animals; D003964:Diaphragm / Q000187:drug effects*; D005071:Evoked Potentials / Q000187:drug effects; D005221:Fatigue / Q000503:physiopathology; D005260:Female; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D010197:Pancuronium / Q000008:administration & dosage / Q000494:pharmacology*; D010791:Phrenic Nerve / Q000187:drug effects*; D011930:Reaction Time; D011950:Receptors, Cholinergic / Q000187:drug effects; D013997:Time Factors; D014403:Tubocurarine / Q000008:administration & dosage / Q000494:pharmacology*; D014673:Vecuronium Bromide / Q000008:administration & dosage / Q000494:pharmacology*
D011950:Receptors, Cholinergic; D014673:Vecuronium Bromide; D010197:Pancuronium; D014403:Tubocurarine