Barbin G, Palacios J M, Garbarg M, Schwartz J C, Gaspar P, Javoy-Agid F, Agid Y
J Neurochem. 1980 Aug;35(2):400-6. doi: 10.1111/j.1471-4159.1980.tb06278.x.
The properties of the histamine-forming enzyme in human brain samples were studied utilizing a radiochromatographic procedure. The influence of postmortem conditions was checked with rat brains, and the results indicated that the enzyme activity is not altered in situ for a delay not exceeding 4 h at ambient temperature. Moreover, tissue blocks or homogenates can be stored at temperatures for up to 3 months with a good preservation of the enzyme activity. The data indicate that histamine synthesis in the human brain involves the "specific" histidine decarboxylase (HD, EC 4.1.1.22) and not the aromatic L-amino acid decarboxylase: (1) the optimum pH is 7.4 at 10(-6) M-L-histidine; (2) the apparent Km is about 3.10(-5) M; (3) it is inhibited by alpha-hydrazino histidine and brocresine but not affected by alpha-methyl DOPA. Moreover, a major portion of the enzyme is localized in a subcellular fraction containing nerve terminals and it shows an uneven regional distribution which parallels that observed in the brain of other mammalian species. Taken together these data strongly suggest that histamine could play a neurotransmitter role in the human brain.
利用放射色谱法研究了人脑样本中组胺形成酶的特性。用大鼠脑检测了死后条件的影响，结果表明，在环境温度下延迟不超过4小时，酶活性在原位不会改变。此外，组织块或匀浆可在低温下保存长达3个月，酶活性保存良好。数据表明，人脑中组胺的合成涉及“特异性”组氨酸脱羧酶（HD，EC 4.1.1.22），而非芳香族L-氨基酸脱羧酶：（1）在10（-6）M-L-组氨酸时，最适pH为7.4；（2）表观Km约为3.10（-5）M；（3）它被α-肼基组氨酸和溴克辛抑制，但不受α-甲基多巴影响。此外，该酶的大部分位于含有神经末梢的亚细胞组分中，并且显示出不均匀的区域分布，这与在其他哺乳动物物种脑中观察到的情况相似。综合这些数据强烈表明，组胺可能在人脑中发挥神经递质的作用。
