1971 年 67 巻 5-6 号 p. 452-466
Effects of Thalamonal, Fentanyl, Droperidol and Morphine upon the somato motor activity in the cat, endplate potential and membrane potential in the muscle fiber of the frog were studied and compared with each others.
1. Thalamonal (0.5ml/kg) and Fentanyl (0.04mg/kg) depressed the spinal polysynaptic reflex activity strikingly in the high spinal cat (Th1) leaving the monosynaptic reflex activity (MSR) uninfluenced even at a larger doses.
2. In the spinal cat, inhibition of the exensor MSR induced by the cutaneous nerve (sural, saphenous nerve) stimulation was abolished by Thalamonal, Fentanyl and Morphine, but not by Droperidol.
3. The tonic muscle activity of the neck in the decerebrate cat was depressed immediately after injection of Thalamonal (0.06ml/kg) Fentanyl (0.01mg/kg) and Droperidol (0.5mg/kg). Also the spontaneous efferent fusimotor activity recorded from split thin filament of L7 in the pentobarbitalized cat was abolished by 0.1ml/kg doses of Thalamonal.
4. Action potential of the sciatic nerve in the frog was reduced to 75.1±3.6% of the control size by 10-1v/v of Thalamonal and was depressed to 62.0±17.0% of the control by 2.5×10-5w/v of Droperidol. Fentanyl and Morphine at a concentration of 10-4w/v were not effective.
5. Twitch tension in the gastrocnemius muscle preparation and the end plate potential (E. P. P.) of the d-tubocurarine treated sartorius muscle of the frog were depressed by Thalmonal (10-2v/v) and Fentanyl (10-5w/v).
6. The resting membrane potential in the isolated frog sortorius muscle was not influenced by Fentanyl (10-2w/v) and Morphine (10-4w/v). By Droperidol (10-4w/v) the resting potential was slightly reduced. The spike potential evoked by intracellularly applied polarizing pulse became smaller in size by Thalamonal (2×10-3v/v) and Droperidol (1×10-5w/v). Fentanyl (1×10-4w/v) and Morphine (1×10-4w/v) had no significant effect.