It is now generally recognized that renal failure or impaired renal function requires changes in the dosage regimen of many drugs to prevent drug accumulation and toxic effect. Further-more, it has been shown that large single dose or multiple do,,a 3 of d-tubocurarine increases the duratoin of neuromuscular blocking effect.
In order to study the influence of renal funtion on the neuromuscular blocking effect of large single dose of d-tubocurarine, the duration of action was measured by single-twitch response using cat´s sciatic nerve-gastrocnemius muscle preparation. Twenty four cats were used for this study and subdivided into 3 groups: group I; control, group II; unilateral renal pedicle ligation, group III; bilateral renal pedicle ligation. The animals \rere anesthetized with intramuscular injection of nembutal, 60mg/kg. Following tracheostomy and intubation, the lungs were artificially ventilated with room air to deliver 40m1/kg at a rate of 20 breaths/minute. And a stable pH (7.30-7.45) was maintained throughout the experiment. The body temperature was kept at 35-37C by thermoblanket. An infusion of Ringer´s lactate solution was started at a rate 10 drops/minute.
The degree of neuromuscular block and time inteval taken to 25% (T25)´, 50o (T50), 15o (T75), and 90o(T90) recovery of control twitch height were measured after intravenous injection of d-tubocurarine lmg/kg. The sciatic nerve was stimulated supramaximally by a single stimulus with square waves. (0.2 msec duration, 0. 1Hz frequency)
The results were as follows;
1) The time of neuromuscular blockade at 100% depression was 373 sec in group I, 340 sec in group II, and 336 sec in group I11. No significant time difference was observed between each groups.
2) The mean spontaneous recovery time to T90 was 107 min in group I, 214 min in group II,
and 444 min in group III. Significant time difference was observed each groups.
3) In the absence of renal funtion, prolonged neuromuscular block effect would be occured
in case of administration of large single dose of d-tubocurarine.
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