The characterisation of [3H]GABA uptake into the satellite glial cells of rat sensory ganglia
The characterisation of [3H]GABA uptake into the satellite glial cells of rat sensory ganglia
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大鼠感觉神经节卫星胶质细胞摄取 [3H]GABA 的表征
DOI：
10.1016/0006-8993(74)90147-4
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发表时间：
1974
期刊：
影响因子：
2.9
通讯作者：
["F. Schon
中科院分区：
文献类型：
--
作者：
["F. Schon
[~ 3 H]GABA在体外大鼠感觉神经节内的蓄积仅局限于卫星胶质细胞。使用浓度为1 × 10− 7 M的GABA，在存在10 μM氨基氧乙酸（AOAA）的情况下，摄取持续线性4 h，达到100：1的组织/培养基比;在不存在AOAA的情况下，摄取在2 h后开始饱和，组织/培养基比为25：1。1.吸收似乎是由动力学饱和过程介导的，表观Km为10μM（高亲和力）药物抑制研究表明，GABA受体拮抗剂荷包牡丹碱和印防己毒素或某些GABA类似物和其它药理学试剂的抑制特性的详细比较揭示了皮层切片和感觉神经节之间的直接差异。1 - 2，4-二氨基丁酸作为皮层切片中的摄取抑制剂比作为感觉神经节中的摄取抑制剂有效20倍;相反，β-丙氨酸作为感觉神经节摄取抑制剂有效200倍。氯丙嗪和对氯汞苯磺酸对感觉神经节的抑制作用远低于皮层脑片。总之，感觉神经节胶质细胞的摄取过程与皮层神经元的摄取过程有一定的差异。GABA在神经节中的摄取速率比在皮质中慢得多。这可能是由于神经节中的Vmax值较低而导致的，这表明摄取位点稀疏。在AOAA的存在下，神经节摄取大大增强，这意味着GABA被GABA：谷氨酸转氨酶酶快速catalysts进入神经胶质细胞。药物敏感性的差异表明两种主动转运系统表现出不同的结合位点。
The accumulation of [3H]GABA in rat sensory gangliain vitrois exclusively localised within satellite glial cells. Using a GABA concentration of 1 × 10−7M, the uptake continued linearly for 4 h in the presence of 10 μM amino-oxyacetic acid (AOAA) attaining a tissue/medium ratio of 100:1; in the absence of AOAA the uptake started to saturate after 2 h, the tissue/medium ratio being 25:1.The uptake appeared to be mediated by a kinetically saturable process with an apparentKmof 10μM(high affinity) and was extremely dependent on the presence of external sodium ions.Drug inhibition studies indicated that the high affinity uptake was not inhibited by the GABA receptor antagonists bicuculline and picrotoxin or by the amino acids glutamate, glycine or glutamine.Detailed comparison of the inhibition properties of certain GABA analogues and other pharmacological agents revealed direct differences between cortical slices and sensory ganglia.l-2,4-Diaminobutyric acid was 20 times more potent an inhibitor of uptake in cortical slices than in sensory ganglia; conversely β-alanine was 200 times more potent an inhibitor of sensory ganglion uptake. Chlorpromazine andp-chloromercuriphenyl sulphonate were far less potent inhibitors of the ganglia than the cortical slices.In conclusion the uptake process of glial cells in sensory ganglia shows certain distinct differences from that of cortical neurones. The rate of GABA uptake in the ganglia is much slower than in the cortex. This may result from the low Vmaxvalue in the ganglia indicating a sparsity of uptake sites. The ganglion uptake is greatly enhanced in the presence of AOAA implying a rapid catabolism of GABA taken into glial cells by the enzyme GABA: glutamate transaminase. The differences in drug sensitivity indicate that the two active transport systems exhibit different binding sites.