Schultzberg M, Segura-Aguilar J, Lind C
Department of Pathology, Karolinska Institute, Huddinge University Hospital, Sweden.
Neuroscience. 1988 Dec;27(3):763-76. doi: 10.1016/0306-4522(88)90181-9.
DT diaphorase [NAD(P)H:quinone oxidoreductase] activity was measured in subcellular fractions from homogenates of striatum, frontal cortex, hippocampus, cerebellum, hypothalamus and substantia nigra. This flavoprotein, which by definition oxidizes dihydronicotinamide adenine dinucleotide and dihydronicotinamide adenine dinucleotide phosphate at equal rates and is completely inhibited by 10(-5) M dicoumarol, was found to constitute 80-90% of the total dihydronicotinamide adenine dinucleotide- and dihydronicotinamide adenine dinucleotide phosphate-reductase activities in all brain regions studied. Antibodies raised against purified cytosolic DT diaphorase from the rat liver cross-reacted with the brain enzyme and inhibited soluble DT diaphorase from striatum and cerebellum to 80-90%. Immunohistochemical studies with the same antibodies demonstrated the occurrence of DT diaphorase immunoreactivity in a population of neurons in the substantia nigra and ventral tegmental area. In some neurons there was a colocalization of DT diaphorase and tyrosine hydroxylase-like immunoreactivity. The dense network of DT diaphorase-immunoreactive fibres in the striatum disappeared along with the dopaminergic innervation after 6-hydroxydopamine lesion. DT diaphorase immunoreactivity was also found in Bergmann glia, astrocytes and tanycytes. No correlation appeared to exist between the localization of neuronal DT diaphorase immunoreactivity and the dihydronicotinamide adenine dinucleotide phosphate-diaphorase-like activity, as defined by tetrazolium salt staining, used as a marker for certain peptidergic and cholinergic neurons. However, in, for example, glial cells in the cerebellum, DT diaphorase might contribute or be responsible for the histochemical dihydronicotinamide adenine dinucleotide phosphate-diaphorase activity.
在纹状体、额叶皮质、海马体、小脑、下丘脑和黑质匀浆的亚细胞组分中测量了DT黄递酶[NAD(P)H：醌氧化还原酶]活性。这种黄素蛋白按照定义以相同速率氧化二氢烟酰胺腺嘌呤二核苷酸和二氢烟酰胺腺嘌呤二核苷酸磷酸，并且被10(-5)M双香豆素完全抑制，发现在所有研究的脑区中，它占总二氢烟酰胺腺嘌呤二核苷酸和二氢烟酰胺腺嘌呤二核苷酸磷酸还原酶活性的80-90%。用从大鼠肝脏纯化的胞质DT黄递酶产生的抗体与脑酶发生交叉反应，并将纹状体和小脑的可溶性DT黄递酶抑制80-90%。用相同抗体进行的免疫组织化学研究表明，黑质和腹侧被盖区的一群神经元中存在DT黄递酶免疫反应性。在一些神经元中，DT黄递酶和酪氨酸羟化酶样免疫反应性存在共定位。6-羟基多巴胺损伤后，纹状体中DT黄递酶免疫反应性纤维的致密网络随着多巴胺能神经支配一起消失。在伯格曼胶质细胞、星形胶质细胞和伸长细胞中也发现了DT黄递酶免疫反应性。神经元DT黄递酶免疫反应性的定位与用作某些肽能和胆碱能神经元标志物的四氮唑盐染色所定义的二氢烟酰胺腺嘌呤二核苷酸磷酸黄递酶样活性之间似乎没有相关性。然而，例如在小脑中的胶质细胞中，DT黄递酶可能有助于或负责组织化学二氢烟酰胺腺嘌呤二核苷酸磷酸黄递酶活性。
