Schousboe A, Frandsen A, Drejer J
Department of Biochemistry A, Panum Institute, University of Copenhagen, Denmark.
Neurochem Res. 1989 Sep;14(9):871-5. doi: 10.1007/BF00964817.
Evoked release of [3H]-D-aspartate which labels the neurotransmitter glutamate pool in cultured cerebellar granule cells was compared with evoked release of adenosine from similar cultures. It was found that both adenosine and [3H]-D-aspartate could be released from the neurons in a calcium dependent manner after depolarization of the cells with either 10-100 microM glutamate or 50 mM KCl. Cultures of cerebellar granule cells treated with 50 microM kainate to eliminate GABAergic neurons behaved in the same way. This together with the observation that cultured astrocytes did not exhibit a calcium dependent, potassium stimulated adenosine release strongly suggest that cerebellar granule cells release adenosine in a neurotransmitter-like fashion together with glutamate which is the classical neurotransmitter of these neurons. Studies of the metabolism of adenosine showed that in the granule cells adenosine is rapidly metabolized to ATP, ADP, and AMP, but in spite of this, adenosine was found to be released preferential to ATP.
将标记培养的小脑颗粒细胞中神经递质谷氨酸池的[3H]-D-天冬氨酸的诱发释放与来自相似培养物的腺苷的诱发释放进行了比较。结果发现，在用10-100微摩尔谷氨酸或50毫摩尔氯化钾使细胞去极化后，腺苷和[3H]-D-天冬氨酸都能以钙依赖的方式从神经元中释放出来。用50微摩尔红藻氨酸处理以消除GABA能神经元的小脑颗粒细胞培养物表现出相同的方式。这与培养的星形胶质细胞未表现出钙依赖的、钾刺激的腺苷释放这一观察结果一起，强烈表明小脑颗粒细胞以类似神经递质的方式释放腺苷，同时释放谷氨酸，而谷氨酸是这些神经元的经典神经递质。对腺苷代谢的研究表明，在颗粒细胞中，腺苷迅速代谢为ATP、ADP和AMP，但尽管如此，发现腺苷比ATP更优先释放。
