斷頭家兎保生腦髓灌流法に就て

A Method to Keep a Decapited Rabbits Cerebrum alive by Irrigating Fluid

緒言

　實驗醫學の領域に於いて，生體の各種臓器組織に就きその固有の生理的並に病的機能を同一個體につき他の臓器組織の影響を受ける事なく知る事は非常に重要な事である。此の理想に最も近い方法の一つとして灌洗實驗が學げられる。

　1859年Loebell^1）氏が始めて豚の肝臓に就き灌流實驗を試み，爾來肝臓，心臓，脾臓，腸管，肺臓或は四肢虫垂等種々の臓器組織の灌流實驗が相繼いで行われるに至つた。

　中樞神經系統の灌流實驗については1899年Gies^2）氏は生理學的見地より，貧血時の腦刺激感受性に關する實驗に蟇，蛙，家免，犬を用い，「リンゲル」氏液を腹腔血管より加壓注入し或は頸動脈より心搏を利用して中樞神經系統の開放式灌流を行い，急激に貧血が起ると全身痙攣を表し，徐々に起ると冷血動物では呼吸，皮膚反射眼瞼反射，鼻腔反射，心搏動の順に消失し，温血動物では眼瞼反射，呼吸，鼻腔反射，心搏動の順に消失すると報告している。1900年Verworn^3），氏は蛙を用いSpin　dler　＆　Hoyerの「ポンプ」により直接大動脈球部より灌流液を注入し，硝酸「ストリヒニン」による興奮，麻痺の状態を腓腸筋並に諸種反射機能に就いて觀察した。Ries^4）氏は蛙を用い大動脈球部心室に夫々輸入及輸出用「カニューレ」を挿入して灌流實驗を行い，鹽類溶液は中樞並に末梢神經の興奮性及筋肉の作動能力を保つ事は出來ないが血性蛋白を含有する灌流液は此等を維持する事が可能であると言う。Schmidt^5）氏は蛙の腹部大動靜脈を結紮し中樞神經系統を含む部分と含まぬ部分との二つの循環系に分かち灌流實驗をなし，藥物の中樞性並に末梢性血管作用を實驗した。Jacobj　＆　Roemer^6）氏は蛙の心室を開き大動脈球部に「カニューレ」を挿入し，Spindler　＆　Hoyerの「ポンプ」を使用し全身を灌流して「ヴェロナール」の藥理作用を檢査して居る。

　Winterstein^7）氏はVerwornの方法により麻酔に關する研究を蛙に就いて行いGerlach　^8）氏は略々同樣の方法により灌流液注入時の律動性の必要の有無を色々の方向から詳しく檢討している。又本邦では溝口，北川^9）新田^10）の諸氏が蟇蛙を用い，後大靜脈より灌流液を注入し動物自己の心臓の「ポンプ」作用を利用する中樞神經心臓灌流法を考案し，藥理學的試驗を行つている。

　以上の如く主として蟇，蛙を用いた開放式灌流法に依る中樞神經系統の生理學的並に藥理學的實驗は古くから行われているが，生化學の立場より中樞神經系統のみを灌流しその物質代謝を追究せんとする試み，特に温血動物の腦髄の血液による灌流實驗はその記載を見ない。

　私は腦髄の生化學的研究の目的を以て斷頭家兎保生腦髄灌流法を考案し一應の成功を見た。未だ極めて不備且不完全な點はあるが，腦組織よりの單なる定性及定量法或いは組織切片及組織粥を以てする化學變化の追及或は組織化學法等從來の方法と異り，本法が最も生體に近い條件に於ける腦髄の物質代謝を追究し得る新しい方法の一つであると信じ，此處に報告し諸賢の御叱正を乞う次第である。

For the purpose of a biochemical Studying of the brain a method of irrigating the rabbit brain was devised and some success was gotten by this method.

In other organs extirpated specimens can be used, but in the brain it is impossible to do so from its anatomical point, therefore a sca-ffolded head was used here instead.

The apparatus that used was a very simple one. It had an invariable bath, a funnel, an artificial lung, a fluid collecting bottle, a double direction stop-cock, a syringe, a glass siphon to keep the temperature constant, and so fars. First, both carotid arteries were ligated and then the iriigating fluid was installed through the glass tube fixed to both common carotid arteries.

The fluid flowing out from the ends of the veins were gathered by a funnel and passed through the artfficial lung and put into the collecting bottle and was again installed with a syringe, The irrigating fluid was made from fibrin removed blood taken from the same rabbit and diluted three times by Ringer's solution. There was a problen whether such irrigating solution would circulate equally th-rough the capillary vessels of the whole brain. This was tested by using the same fluid co- lored with methylen blue and was proved that it circulated even through the smallest kapillary vessels in the cortex and the arach-noidal vessels.

Through this method it was studied if such irrigated brain had any ability of living and if any metabolism was performed. Some glucose solution was added to the irrigating fluid and the consumption of the blood sugar was studi-ed for this purpose. It was found that about 40% was spent after 30minutes of irrigation.

And EEG was taken from surface of such irrigating brain, and to see if they were EEG, the influence of cardiazol and sound were examined. And to make a comparison, another EEG was taken from that using only Ringer's solution, but from this no partcular waves appeared.

EEG was also taken from the rabbit before it was scaffolded and there was a resemblance between the first one and this. From this point it is thought that the former one the brain being irrigated is giving out EEG waves.

From the upper facts, it could be thought that this is the nearest condition to living body to study the metabolism of the brain. The possible time for experimentation at present is 30 minutes, but if the pressure at the time when the fluid is installed and the kind of solution to be used are studied and the appa-rtus is improved, still more possibility of getting a better result is expected.