Koyama Y, Kimura Y, Baba A
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Osaka University, Suita, Japan.
Neurosci Lett. 1997 Feb 14;223(1):65-8. doi: 10.1016/s0304-3940(97)13393-6.
Effect of L-alpha-aminoadipate (L alpha AA), a gliotoxic L-glutamate analogue, on glutamine synthetase (GS) activity of rat cultured astrocytes was examined, L alpha AA at sub-toxic concentrations (less than 0.5 mM, for 48 h) increased GS activity of cultured astrocytes. This increase was prevented by 10 microM cycloheximide, an inhibitor of protein synthesis. L alpha AA increased GS activities of astrocytes cultured in three different conditions, i.e. 12-day-old, 5-233k-old and dibutyryl cAMP(DBcAMP)-induced differentiated cultures. Insulin (10 micrograms/ml) and hydrocortisone (10 microM) increased GS activity of 12-day-old cultured cells, but not that of 5-weeks-old and DBcAMP-treated cells. The increase in GS activity was observed after a transient treatment with L alpha AA for 4 h. These results show that the induction of GS by L alpha AA is not related to developmental stages of astrocytes in culture.
研究了具有神经毒性的L-谷氨酸类似物L-α-氨基己二酸（L alpha AA）对大鼠培养星形胶质细胞谷氨酰胺合成酶（GS）活性的影响。亚毒性浓度（低于0.5 mM，处理48小时）的L alpha AA可增加培养星形胶质细胞的GS活性。这种增加被蛋白质合成抑制剂10 microM放线菌酮所抑制。L alpha AA增加了在三种不同条件下培养的星形胶质细胞的GS活性，即12日龄、5周龄和二丁酰环磷腺苷（DBcAMP）诱导分化的培养物。胰岛素（10微克/毫升）和氢化可的松（10 microM）增加了12日龄培养细胞的GS活性，但未增加5周龄和DBcAMP处理细胞的GS活性。在用L alpha AA短暂处理4小时后观察到GS活性增加。这些结果表明，L alpha AA对GS的诱导与培养星形胶质细胞的发育阶段无关。
