1966 Volume 86 Issue 9 Pages 836-840
A new method for evaluating local anesthetic action was devised. The apparatus is equipped with compartment box shown in Fig.1, which enabled the frog sciatic nerve fibers to be perfused with saline solution with or without anesthetics. Frog sciatic nerve fibers, following elimination of epineurium, were perfused initially with saline solution followed by an anesthetic solution until the action potential of nerve fibers dropped to one-half the initial potential which had been set at 400 μV. At this stage perfusion was made with the initial saline solution until the action potential recovered by 100 μV. The time required for 50% reduction of the initial action potential was recorded as the "onset time of anesthesia, " and the time required for recovery of action potential by 100 μV as "effective duration of the anesthesia." One-half blocking concentration of anesthetics was determined from the dose-reponse curve thereby obtained. Three local anesthetics were evaluated in terms of onset time, effective duration, and a half-blocking concentration.
