Liu L, Feng Y P
Department of Pharmacology, Chinese Academy of Medical Sciences, Beijing.
Yao Xue Xue Bao. 1993;28(12):881-5.
The effects of AMG-1 [6(5-hydroxy-2-methylpyridylamino)-9 ribofranosylpurine], an adenosine analogue, and adenosine on Ca2+-dependent and independent release of glutamate from rat synaptosomes induced by KCl 30 mmol.L-1 were studied with an enzyme-linked fluorometric assay. The synaptosomes were prepared and preincubated for 30 min at 37 degrees C. Two ml of incubation mixture containing synaptosomes (1.27 mg protein), NADP+ 1 mmol.L-1, L-glutamic dehydrogenase 50 U, CaCl2 1.3 mmol.L-1 (or EGTA 1.3 mmol.L-1) was transferred to the stirred cuvette in the fluorometer at 37 degrees C for 5 min. Then, AMG-1 (or adenosine) was added. Released glutamate (eg. fluorescent intensity) was monitored following the addition of 30 mmol.L-1 KCl. The results indicate that Ca2+-dependent glutamate release from depolarized synaptosomes is inhibited by AMG-1 (0.1 mmol.L-1) or adenosine (0.3 mmol.L-1). The action of AMG-1 seems to be similar to that of adenosine. However, no change was found on Ca2+-independent release of glutamate. This implies that the protective effect of AMG-1 against cerebral ischemia may be partially due to inhibiting glutamate release from nerve terminal via the activation of adenosine A1 receptor.
采用酶联荧光分析法研究了腺苷类似物AMG-1 [6(5-羟基-2-甲基吡啶氨基)-9-核糖基嘌呤]和腺苷对30 mmol.L-1氯化钾诱导的大鼠突触体中谷氨酸钙依赖性和非钙依赖性释放的影响。制备突触体并在37℃预孵育30分钟。将含有突触体(1.27 mg蛋白质)、1 mmol.L-1 NADP+、50 U L-谷氨酸脱氢酶、1.3 mmol.L-1氯化钙(或1.3 mmol.L-1 EGTA)的2 ml孵育混合物转移至37℃荧光计中搅拌的比色皿中5分钟。然后加入AMG-1(或腺苷)。加入30 mmol.L-1氯化钾后监测释放的谷氨酸(如荧光强度)。结果表明，AMG-1(0.1 mmol.L-1)或腺苷(0.3 mmol.L-1)抑制去极化突触体中钙依赖性谷氨酸释放。AMG-1的作用似乎与腺苷相似。然而，未发现谷氨酸非钙依赖性释放有变化。这意味着AMG-1对脑缺血的保护作用可能部分归因于通过激活腺苷A1受体抑制神经末梢谷氨酸释放。
