Hallermayer K, Harmening C, Hamprecht B
J Neurochem. 1981 Jul;37(1):43-52. doi: 10.1111/j.1471-4159.1981.tb05289.x.
The cellular distribution of glutamine synthetase was determined by indirect immunofluorescence in cultures of dissociated brain cells from newborn mice. The enzyme could be detected in about 40% of all cells, among which cells with astrocytic morphology were clearly identified. Treatment with the glucocorticoid dexamethasone led to a strong increase in the number of positivity stained cells. Enzyme induction by dexamethasone was maximal after 36 h and at a concentration of 0.1 micrometer. Under these conditions glutamine synthetase specific activity was elevated about six fold. Steroid hormones other than corticosteroids had no effects. The basal activity in these cultures was near that found in brains of newborn mice, but far below the activity in adult brains, showing that in culture the normal development of these cells is disturbed. A comparison of glial and neuronal cell lines showed that glutamine synthetase is present in both types of cell lines at a very low specific activity. Inducibility of this enzyme by dexamethasone was found in glial but not in neuronal cell lines.
通过间接免疫荧光法测定新生小鼠离体脑细胞培养物中谷氨酰胺合成酶的细胞分布。在所有细胞中约40%可检测到该酶，其中可清楚识别出具有星形胶质细胞形态的细胞。用糖皮质激素地塞米松处理导致阳性染色细胞数量大幅增加。地塞米松诱导酶在36小时后且浓度为0.1微摩尔时达到最大值。在这些条件下，谷氨酰胺合成酶的比活性提高了约六倍。除皮质类固醇外的其他类固醇激素无作用。这些培养物中的基础活性接近新生小鼠大脑中的活性，但远低于成年大脑中的活性，表明在培养中这些细胞的正常发育受到干扰。对胶质细胞系和神经元细胞系的比较表明，两种细胞系中谷氨酰胺合成酶的比活性都非常低。地塞米松可诱导该酶活性，在胶质细胞系中可诱导，但在神经元细胞系中则不能。
