脳皮質切片のカリウム効果におよぼすトリエチル錫の影響について

EFFECT OF TRIETHYLTIN ON POTASSIUM-STIMULATED OXYGEN UPTAKE OF RAT BRAIN CORTEX SLICES

はじめに

　Triethyltin （以下TETと略す）は中枢神経系に特異的に作用し，組織学的には白質に広汎な浮腫を形成する^1）2）3）ことによつて多くの研究者の興味をひいて来た。著者は，すでに，TETの組織呼吸並びに蛋白代謝に及ぼす影響を検索し，TET-sulfateを連日腹腟内に注射した成猫の脳白質において，浮腫の著明な時期に蛋白代謝の著明な亢進が見られることを報告し^4），他の作製法による浮腫脳においても蛋白代謝の亢進が見られるという報告^5）6）7）と関連して検討を加えて来た。

　TETの呼吸抑制作用に対して中枢神経組織が強い感受性を示すことを検討してゆくうちに，中枢神経組織に特異的に見られ，細胞の膜機能と密接な関係があると考えられている^{8）9）10）}高カリウムによる刺激呼吸（カリウム効果）とTETとの関係について検討したいと考えた。

Slices of rat brain cortex were incubated in Krebs-Ringer phosphate medium with 10 mM glucose, and the respiratory activity was measured using the standard Warburg manometric technique. After 30 minute-incubation, the concentration of KCl in themedium was elevated to 105 mM to estimate the potassium effect. To study the effect of triethyltin (TET), TET-sulface was added to the medium or it was injected intraperitoneally to rats at the daily dose of 2 mg/kg body weight for one to three days.

1) When TET was added at lower concentration (5 × 10^-6 More), the oxygen uptake of rat brain cortex slices was slightly increased in normal media, but it was supressed in media containing 105 mM KCl (which stimulates normal brain respiration.)

2) Similarly with administration of TET in vivo, oxygen uptake of rat brain cortex slices was inhibited to a greater extent in media containing 105 mM KC1 than in normal media.

3) While rat liver slices and rat brain cortex homogenate were not supressed by TET to a greater extent in the presence of 105 mM KC1 than in normal media.