Desjardins P, Todd K G, Hazell A S, Butterworth R F
Neuroscience Research Unit, CHUM (Campus Saint-Luc), Montreal, Quebec, Canada.
Neurochem Int. 1999 Nov;35(5):363-9. doi: 10.1016/s0197-0186(99)00082-0.
"Peripheral-type" benzodiazepine receptors (PTBRs) are highly expressed on the outer mitochondrial membrane of several types of glial cells. In order to further elucidate the nature of the early glial cell changes in thiamine deficiency, PTBR sites and PTBR mRNA were measured in thalamus, a brain structure which is particularly vulnerable to thiamine deficiency, of thiamine-deficient rats at presymptomatic and symptomatic stages of deficiency. PTBR sites were measured using an in vitro binding technique and the selective radio ligand [3H]-PK11195. PTBR gene expression was measured by RT-PCR using oligonucleotide primers based upon the published sequence of the cloned rat PTBR. Microglial and astrocytic changes in thalamus due to thiamine deficiency were assessed using immunohistochemistry and antibodies to specific microglial (ED-1) and astrocytic (GFAP) proteins respectively. Significant increases of [3H]-PK11195 binding sites and concomitantly increased PTBR mRNA were observed in thalamus at the symptomatic stage of thiamine deficiency, coincident with severe neuronal cell loss and increased GFAP-immunolabelling (indicative of reactive gliosis). Positron Emission Tomography using 11C-PK11195 could provide a novel approach to the diagnosis and assessment of the extent of thalamic damage due to thiamine deficiency in humans with Wernicke's Encephalopathy.
“外周型”苯二氮䓬受体（PTBRs）在几种类型的神经胶质细胞的线粒体外膜上高度表达。为了进一步阐明硫胺素缺乏时早期神经胶质细胞变化的本质，在硫胺素缺乏大鼠硫胺素缺乏的症状前期和症状期，对丘脑（一种特别易受硫胺素缺乏影响的脑结构）中的PTBR位点和PTBR mRNA进行了测量。使用体外结合技术和选择性放射性配体[3H]-PK11195测量PTBR位点。使用基于已发表的克隆大鼠PTBR序列的寡核苷酸引物，通过RT-PCR测量PTBR基因表达。分别使用免疫组织化学和针对特定小胶质细胞（ED-1）和星形胶质细胞（GFAP）蛋白的抗体，评估硫胺素缺乏导致的丘脑中的小胶质细胞和星形胶质细胞变化。在硫胺素缺乏的症状期，丘脑中观察到[3H]-PK11195结合位点显著增加，同时PTBR mRNA也增加，这与严重的神经元细胞丢失和GFAP免疫标记增加（提示反应性胶质增生）相一致。使用11C-PK11195进行正电子发射断层扫描可为诊断和评估韦尼克脑病患者因硫胺素缺乏导致的丘脑损伤程度提供一种新方法。
