脳の遊離アミノ酸について(X) 成熟ヒト脳およびヒト胎児脳各部位における遊離アミノ酸およびその関連物質について

イオン交換クロマトグラフイーをもちいて,妊娠5ケ月および8ケ月胎児脳の各部位ならびに18才結節性硬化症患者脳の前頭葉,腫瘍周辺の非結節性組織について遊離アミノ酸およびその関連物質を各々分離定量した. 1) 妊娠5ケ月なうびに8ケ月胎児脳と成熟ヒト脳を比較すると,胎児脳と生後ヒト脳との間にはその遊離アミノ酸量にかなり著明な差異を認める. 2) 胎児脳では,脳各部位ともに多少の例外はあるが,生育の段階につれてタウリン,ホスホエタノラミン,グリシン,アラニン等は減少し,グルタミン酸,アスパラギン酸, γ-アミノ酪酸等は増加する傾向を示している. 3) γ-アミノ酪酸は胎児脳のいずれでも,視床下部で最高値を示した. 4) 生後のヒト脳で多量に測定され得るシスタチオニンは胎児脳にはほとんど存在しない.

With the brains of foetuses on the fifth gravid month and on the eighth gravid month the author isolated and estimated the free amino-acids and related substances at various parts of these brains by means of the ion-exchange chromatography, and conducted the same investigations with the normal tissues surrounding the tumor of the frontal lobe in the brain of an 18-year-old patient with tubosclerosis. 1. The quantities of free amino-acids in the foetal brains differ significantly from those in the mature human brain. 2. In the foetal brain, with some variations according to sites, amino-acids such as taurine, phosphoethanolamine, glycine and alanine, generally tend to decrease with the advance in age, while glutaminic, aspartic and γ-amino-butyric acids tend to increase. 3. In either one of the foetal brains γ-amino-butyric acid is detected in a largest quantity in the hypothalamus. 4. Cystathionine which is often detected in a large quantity in the human brain after birth can hardly be recognized in the foetal brain.