Karhunen T, Tilgmann C, Ulmanen I, Panula P
Department of Anatomy, University of Helsinki, Finland.
Int J Dev Neurosci. 1995 Dec;13(8):825-34. doi: 10.1016/0736-5748(95)00070-4.
Previous biochemical and histochemical studies have suggested that catechol-O-methyltransferase (COMT) is a predominantly glial enzyme in the brain. The aim of this work was to study its localization and molecular forms in primary cultures, where cell types can be easily distinguished with specific markers, COMT immunoreactivity was studied in primary astrocytic cultures from newborn rat cerebral cortex, and in neuronal cultures from rat brain from 18-day-old rat embryos using antisera against rat recombinant COMT made in guinea pig. Double-staining studies with specific cell markers to distinguish astrocytes, neurons and oligodendrocytes were performed. COMT immunoreactivity colocalized with a specific oligodendrocyte marker galactocerebroside in cells displaying oligodendrocyte morphology, flat cells displaying type-1 astrocyte morphology and glial fibrillary acidic protein, in branched cells displaying type-2 astrocyte morphology and in cell bodies of neurons, the processes of which displayed neurofilament immunoreactivity. Western blots detected both soluble 24 kDa and membrane-bound 28-kDa COMT proteins in neuronal and astrocyte cultures. The results suggest that COMT is synthesized by cultured astrocytes, oligodendrocytes and neurons.
以往的生物化学和组织化学研究表明，儿茶酚-O-甲基转移酶（COMT）在大脑中主要是一种胶质细胞酶。这项工作的目的是研究其在原代培养物中的定位和分子形式，在原代培养物中细胞类型可以通过特定标记物轻松区分。使用针对豚鼠制备的大鼠重组COMT的抗血清，研究了新生大鼠大脑皮层原代星形胶质细胞培养物以及18日龄大鼠胚胎大鼠脑神经元培养物中的COMT免疫反应性。进行了用特定细胞标记物区分星形胶质细胞、神经元和少突胶质细胞的双重染色研究。在显示少突胶质细胞形态的细胞、显示1型星形胶质细胞形态的扁平细胞和胶质纤维酸性蛋白、显示2型星形胶质细胞形态的分支细胞以及神经元细胞体中，COMT免疫反应性与特定的少突胶质细胞标记物半乳糖脑苷脂共定位，神经元的突起显示神经丝免疫反应性。蛋白质免疫印迹法在神经元和星形胶质细胞培养物中检测到了可溶性24 kDa和膜结合28 kDa的COMT蛋白。结果表明，COMT由培养的星形胶质细胞、少突胶质细胞和神经元合成。
