ANALYSIS OF GLUTAMATE DECARBOXYLASE IN POSTMORTEM BRAIN-TISSUE IN HUNTINGTONS-CHOREA
ANALYSIS OF GLUTAMATE DECARBOXYLASE IN POSTMORTEM BRAIN-TISSUE IN HUNTINGTONS-CHOREA
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DOI：
10.1016/0022-3956(74)90099-5
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发表时间：
1974-01-01
影响因子：
4.8
通讯作者：
RAYNER, CN
中科院分区：
文献类型：
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作者：
IVERSEN, LL;BIRD, ED;RAYNER, CN
尽管波普在这次研讨会上清楚地回顾了死后人脑组织的生化分析所固有的困难和危险，但我仍然希望对这种直接方法的潜在价值保持乐观。该实验室最近的一项研究可以作为这种分析可行性的一个例子。亨廷顿舞蹈病是一种显性遗传性疾病，临床上出现在生命的第三或第四个十年与异常运动表现，逐步增加，通常与精神病症状。最大的神经病理学变化见于基底神经节，神经元性亨廷顿舞蹈病似乎与多巴胺能过度活跃有关，与帕金森病类似。最近，佩里等人2检查了7例死于亨廷顿舞蹈病的患者的死后大脑，并报道，虽然大多数氨基酸在基底神经节中以正常浓度存在，但抑制性递质γ-氨基丁酸（GABA）在这些组织中显著减少。我们受到这些发现的刺激，试图测量亨廷顿舞蹈病患者死后组织中谷氨酸脱羧酶（GABA的生物合成酶）的活性。据报道，这种酶在死后组织中相对稳定，而GABA浓度在正常脑组织中死亡后迅速增加。亨廷顿舞蹈病患者的大脑中，有14个大脑是在英国各地的精神病顾问医生和病理学家的慷慨合作下获得的。此外，收集了17个对照脑，尽可能与舞蹈病患者死亡前的年龄、性别和不同临床状况匹配，并与死后处理和储存条件匹配。人脑组织和动物大脑的实验证实，谷氨酸脱羧酶在死后是一种非常稳定的酶。在4 ℃下储存长达57小时或在-20 ℃下储存长达6周的组织中，酶活性没有显著损失。死亡和在4 ℃下冷藏之间的平均间隔对于对照脑为4小时（范围1-11小时），对于舞蹈病脑为6小时（范围1-16小时）。随后，在解剖成不同区域并将解剖样品储存在-20 ℃下之前，对照组的间隔时间为29小时（范围为5-64小时），舞蹈病组的间隔时间为28小时（范围为16-48小时）。每个脑的一半被保存用于组织病理学检查。谷氨酸脱羧酶的测量结果，使用放射化学测定程序，包括捕获由羧基标记的L-谷氨酸形成的放射性标记的二氧化碳，总结于
DESPITE the difficulties and dangers inherent in the biochemical analysis of post-mortem human brain tissue so clearly reviewed by Pope in this symposium, I would nevertheless like to remain optimistic about the potential value of this direct approach. A recent study in this laboratory may serve as an example of the feasibility of such analyses. ¹ Huntington's chorea is a dominant inherited disorder which appears clinically in the third or fourth decade of life with abnormal motor manifestations that increase progressively and are commonly associated with psychotic symptoms. The greatest neuropathological changes are seen in the basal ganglia, and neuropharmacologically Huntington's chorea appears to be associated with dopaminergic hyperactivity, as a counterpart to Parkinson's disease.Recently PERRY et al. 2 examined seven post-mortem brains of patients dying with Huntington's chorea, and reported that while most amino acids were present at normal concentrations in the basal ganglia the inhibitory transmitter substance gamma-aminobutyrate (GABA) was significantly reduced in such tissues. We were stimulated by these findings to attempt measurements of the activity of the enzyme glutamate decarboxylase, the biosynthetic enzyme for GABA, in post-mortem tissue from Huntington's chorea. The enzyme had previously been reported to be relatively stable in post-mortem tissues, ³ whereas GABA concentrations increase rapidly after death in normal brain tissue. ª With the generous co-operation of Consultant Psychiatrists and Pathologists throughout the United Kingdom it was possible to obtain 14 brains from patients dying with Huntington's chorea. In addition 17 control brains, matched as closely as possible to the age, sex and varying clinical conditions of the choreic patients prior to death, and matched for the conditions of post-mortem handling and storage were collected. Experiments with human brain tissue, and with animal brains confirmed that glutamate decarboxylase was a remarkably stable enzyme post-mortem. There were no significant losses in enzyme activity in tissue stored for up to 57 hr at 4 C, or up to 6 weeks at− 20 C. The average interval between death and refrigeration at 4 C was 4 hr for control brains (range 1-11 hr) and 6 hr for choreic brains (range 1-16 hr). The subsequent interval before dissection into different regions and storage of the dissected samples at− 20 C was 29 hr (range 5–64 hr) for controls and 28 hr (range 16-48 hr) for choreic brains. One half of each brain was preserved for histopathological examination. The results of measurements of glutamate decarboxylase, using a radiochemical assay procedure involving the trapping of radiolabelled carbon dioxide formed from carboxyl labelled L-glutamate are summarized in