Sherman A D
Department of Psychiatry, University of Iowa College of Medicine, Iowa City 52242.
Neurochem Res. 1989 Jan;14(1):97-101. doi: 10.1007/BF00969765.
Synaptosomes were prepared from whole rat brain by six different methods based on gradients of sucrose, Ficoll or Percoll. In these, the synthesis and calcium-specific release of amino acids were assessed by two different procedures. Preparations based on sucrose showed the least calcium-specific release, followed by Ficoll-derived synaptosomes. As previously described, Percoll gave two separate populations of synaptosomes, both very active in terms of release of aspartate, glutamate, and GABA. The data involving release and synthesis were not identical, but did agree in the following: in low-density synaptosomes, haloperidol blocked both the release and synthesis of glutamate, but was without effect in the heavier population. 2-chloroadenosine and 2-oxoglutarate affected both release and synthesis only in the high-density population. Dopamine blocked aspartate release and synthesis only in the high-density population. These results suggest that haloperidol interferes with glutamate release and synthesis via a mechanism which may not involve adenosine, serotonin, or dopamine.
通过基于蔗糖、聚蔗糖或 Percoll 梯度的六种不同方法从大鼠全脑中制备突触体。在这些方法中，通过两种不同程序评估氨基酸的合成和钙特异性释放。基于蔗糖的制剂显示出最少的钙特异性释放，其次是聚蔗糖衍生的突触体。如前所述，Percoll 产生了两个单独的突触体群体，就天冬氨酸、谷氨酸和 GABA 的释放而言，两者都非常活跃。涉及释放和合成的数据并不相同，但在以下方面是一致的：在低密度突触体中，氟哌啶醇阻断了谷氨酸的释放和合成，但对较重的群体没有影响。2-氯腺苷和 2-氧代戊二酸仅在高密度群体中影响释放和合成。多巴胺仅在高密度群体中阻断天冬氨酸的释放和合成。这些结果表明，氟哌啶醇通过一种可能不涉及腺苷、5-羟色胺或多巴胺的机制干扰谷氨酸的释放和合成。
