摘出蛙腓腸筋労作と重曹水の関係

　緒言

　重曹注射がメニヱル氏病や特発性鼻出血に対して著効があり，その作用機転に就いてはこれ等が末梢動脉痙攣に基因する毛細管及び末梢静脉の過度の拡張による局所の浮腫乃至滲透性出血であり，重曹注射がその原因である動脉攣縮を緩解し効果を発揮するものと考へられている。即ち血管痙攣の緩解は重曹よりの炭酸ガスイオンが血管筋神経移行部（Neuromuscular Junction以後N. J. と略す。）の興奮性を麻痺することにより起されると考へられる。

　著者は筋收縮神経のN. J. と重曹との関係を念頭に置いて摘出せる蛙の腓腸筋に就いて観察を行つた。

　Goto observed that in maintaining muscular contractions in a nerve-muscle preparation saline solution is far superior in contrast to that of sodium bicarbonate. The specimen was prepared from the leg of a frog which weighed 20g.; stimulations were afforded by galvanic current which was interruptedly applied once every second while the preparation was repeatedly bathed in either 0.6 percent saline or 0.4 percent sodium bicarbonate solution as the case may be. In this way fatigue curves were obtained for both agents under the test. With clonic contractions the two agents showed no marked difference. But, in tonic contractions the saline solution far surpassed that of sodium bicarbonate in the period of time in which muscular actions were maintained.