脳のシスタチオニン 第Ⅲ編 脳機能（in vivo）に及ぼすL-シスタチオニンの影響

L-シスタチオニンを動物に投与してその生理作用を見た.フェノバルビタールその他の薬物に対しシスタチオニンは抗麻酔に働くようであるが,電撃痙攣,非麻酔時脳波には影響しない.これはシスタチオニンが先づ肝でシスチンとなり,しかる後に薬物に解毒的に働らくためと解釈され,直接脳内に侵入したシスタチオニンの中枢作用と考えられるような成績は得られなかつた.

The author investigated physiological and pharmacological function of cystathionine that had been detected in the human brain. He studied changes of behavior, respiratory function, blood pressue, electroencephalogram, electroshock threshold and TD(50) of several kinds of drugs after administration of L-cystathionine to mice, rabbits and cats whose brains were perfused through the isolated cerebral circulations. L-cystathionine did not influence the behavior, respiration, blood pressure and electroshock threshold in the experiments with mice and rabbits. On the other hahd, the counteractions of L-cystathionine to the toxic effects of phenobarbital and chlorpromazine were observed in the experiment of TD(50) of such drugs and awaking signes on the EEG of the anaesthetized rabbits after L-cysthionine had been given. No significant effects of it, however, were observed on the EEG of ananaesthetized rabbits or of the cats whose cerebral circulation had been isolated. On the basis of these experiments and preceding reports, the auther assumed as follows, 1) Almost all of the L-cystathionine administered to animals probably was metabolized rappidly to cystine in the liver tissue, and so increased cystine might work to counteract the toxic effects of phenobarbital and other drugs. 2) A little amonnts of L-cystathionine entered into brain through the blood-brain barrier hardly influences on the physiological functions of central nervous system.