Kaoru Kitazawa

Tolerance of repeated anesthesia with ketamine hydrochloride in dogs.

12頭の雑種成犬を用い, 塩酸ケタミン5mg/kgまたは10mg/kgを3日おきに計10回静脈内に反復投与し, その影響を観察した。痛覚回復, 起立および歩行までに要したそれぞれの時間は, 短縮する傾向がみられ, それは耐性の発現によるものと考えられた。血圧, 心拍数, 呼吸数および体温では, 反復投与の影響は観察されず, また他の特記されるべき副作用もみられなかった。これらのことより, ケタミン反復投与のリスクは小さく, 臨床応用が可能であるが, 使用にあたっては, 耐性の発現と投薬量について検討する必要があると思われた。

Effects of pretreatment with oxytetracycline on the duration of pentobarbital anesthesia in dogs.

The effects of pretreatment with oxytetracycline on the recovery from pentobarbit; anesthesia were studied in experimental and control dogs. The experimental dogs wer anesthetized by the injection of pentobarbital (25 mg/kg BW) twice at intervals of 20 days without and with the pretreatment of oxytetracycline (22 mg/kg BW/day) for 4 days. All dogs pretreated with oxytetracycline have revealed the extensive prolongation of recovery from pentobarbital anesthesia regarding not only various neurological findings but behavior and motility. Since the blood findings through these experiments suggested some depression of hepatic functions following the successive pretreatment with oxytetracycline, some disorders in the metabolism of pentobarbital in the liver might be involved in the extension of anesthetic effects of pentobarbital.

Experimental studies on electroacupuncture analgesia (EAA). III. Evoked responses of Motor and Sensory nerves in the chicken under EAA.

演者は犬を用いて針通電麻酔実験をおこない, 効果発現にともなう一連の現象を観察してきた。そのうち針通電麻酔時の神経系の振舞いを脳波, 誘発電位および誘発筋電図を指標に検討してきた。今回は実験動物として取扱いが容易な鶏を用いて、針通電麻酔を試み, その効果を確認したので, 運動神経を刺激して得られる誘発筋電図および知覚神経の誘発反応電位について分析をおこなった。(1) 後肢の経穴のうち「股端」をえらび針通電をおこなうと鎮静し, 鉗圧による反応が低下した。(2) 腓腹筋に誘発されるM波を記録した。針通電初期に振巾は増大し, MCV (運動神経伝導速度) も促進するが, その後は抑制され, 針通電を停止すると比較的すみやかに回復した。(3) 坐骨神経叢近傍で導出される誘発反応電位を加算処理をおこなって記録した。針通電開始にともなって振巾は減少し, かつSCV (知覚神経伝導速度) も遅延した。このような現象は針通電中維持され, 針通電を停止しても数時間にわたって観察された。以上の成績から針通電麻酔により遠心性の情報は一過性の抑制を受けるが, 求心性の情報は針通電停止後も数時間にわたって抑制される。これには生体の神経体液性機構が関与していると思われる。

STUDIES ON ELECTROACUPUNCTURE ANALGESIA (EAA) IN THE DOG

From among the human acupucture points illustrated in a figure, the authors selected four equivalent points, Kyokuchi (Li 11), Inkoten, Ashinosanri (S 36) and Bokoku, in the dog. When needles were inserted at these points to give electric stimulation, analgesia was recognized over a wide part of the body.The present report deals with electrical conditions to obtain analgesia in dogs.1) When an induction stimulator was used, a bilateral pulse wave appeared as an output wave. It was shown as a transformed rectangle wave with a duration of 0.3 msec on the anode side and as a spike wave with a duration of 0.25 msec on the cathode side.The output voltage of that stimulator was 180 VP_P at the maximum, as measured by a synchroscope, and the output current 22 mA.rms at the maximum, as measured by a high-frequency ammeter.2) Some electric conditions for a successful introduction of analgesia were as follows : 15-50 Hz in frequency, 0.5-8.0 VP_P in load voltage, 0.1-5.0 mA.rms in load current, and about 30 minutes as flowing time.3) In order to supply an effective stimulation, it was necessary to select such electrical conditions as to avoid electrolysis of the needle and burning of the tissue.To provide a constant electric stimulation continually a needle had to be fixed firmly. Adequate polarity of electrodes, minimum differences in resistant value among the four electrodes, and appropriate controled techniques for supplying the current were needed to obtain a successful analgesia.