Cis-3-aminocyclohexanecar☐ylic acid: a substrate for the neuronal GABA transport system
Cis-3-aminocyclohexanecar☐ylic acid: a substrate for the neuronal GABA transport system
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Cis-3-氨基环己烷甲酸：神经元 GABA 转运系统的底物
DOI：
10.1016/0006-8993(77)90793-4
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发表时间：
1977
期刊：
影响因子：
2.9
通讯作者：
N. Bowery
中科院分区：
文献类型：
--
作者：
M. Neal;N. Bowery
Fig. 1.神经组织对[3 H] ACHC的摄取。将大脑皮层s（10 mg）、单个视网膜7（约10 mg）或单个去鞘神经节a的切片（0.1 x 0.1 x 2 mm）在5 ml Krebs碳酸氢盐培养基中于指定温度下预孵育10 min。[aH]加入ACHC以得到0.1 μ M的终浓度，并继续孵育。然后回收组织，在25 ℃下在新鲜培养基中洗涤，并转移到计数小瓶中。通过将组织溶解在Soluene-350（Packard）中提取放射性，并通过液体闪烁计数进行测量，通过通道比法校正计数的效率。每个点是4-6个结果的平均值，SEM小于10。交感神经节和脊神经节的结果相同，并标记为“神经节”。[aH]ACHC是最迅速的皮质切片孵育在37 C和组织：培养基的比例几乎12后，实现了30分钟的孵育期。在两个实验中，皮质切片在37 C孵育30分钟期间积累的放射性提取的组织在水中。将匀浆加热至100 ℃ 5分钟并离心.然后对上清液进行色谱分析，结果显示超过95%的放射性对应于真实ACHC，表明累积物质不存在任何代谢。因此，在随后的实验中，将放射性的蓄积作为[aH] ACHC摄取的量度。离体蛙视网膜的GABA摄取是神经元的，但仅限于一小部分特定的细胞（水平细胞）19，该视网膜也积累了[3 H] ACHC（图1），尽管孵育30分钟后，摄取量仅为在相同温度（25 ℃）下孵育的皮质切片的约三分之一。相反，脊神经节和交感神经节（GABA摄取仅限于神经胶质细胞的组织）不蓄积[aH] ACHC（图1）。在这两种类型的神经节中，组织：培养基的比例在孵育60分钟后仅达到0.7，该值表明仅在细胞外水中积累。在大鼠视网膜中，GABA的摄取也主要是神经胶质的，当在37 ℃下孵育时，发现其积累的[3 H] ACHC的量与青蛙视网膜在25 ℃下的积累量大致相同（图1）。乍一看，这一结果与ACHC仅对神经元GABA转运系统具有亲和力不一致，但它是
Fig. 1. Uptake of [3H] ACHC by neural tissues. Slices (0.1 x 0.1 x 2 mm) of cerebral cortex s (10 mg), individual retinae 7 (about 10 mg) or individual desheathed ganglia a were given a preliminary incubation for 10 min at the temperatures indicated in 5 ml Krebs' bicarbonate medium.[aH] ACHC was added to give a final concentration of 0.1/~ M and the incubation continued. The tissue was then recovered, washed in fresh medium at 25 C, and transferred to counting vials. The radioactivity was extracted by dissolving the tissue in Soluene-350 (Packard) and measured by liquid scintillation counting, the counts being corrected for efficier) cy by the channel ratio method. Each point is the mean of 4-6 results and the SEMs were less than 10. The results for sympathetic and spinal ganglia were identical and are labelled'ganglia'.[aH] ACHC was most rapid in cortical slices incubated at 37 C and a tissue: medium ratio of almost 12 was achieved after an incubation period of 30 min. In two experiments, the radioactivity accumulated by cortical slices during 30 min incubations at 37 C was extracted by homogenizing the tissue in water. The homogenate was heated to 100 C for 5 min and centrifuged. The supernatant was then subjected to chromatographic analysis which showed that more than 95~ of the radioactivity corresponded to authentic ACHC, indicating an absence of any metabolism of the accumulated material. Thus, in subsequent experiments the accumulation of radioactivity was taken as measure of [aH] ACHC uptake. The isolated frog retina in which GABA uptake is neuronal but confined to a small specific group of cells (horizontal cells) 19 also accumulated [3H] ACHC (Fig. 1) although, after 30 min incubation, the uptake was only about one-third that of cortical slices incubated at the same temperature (25 C). In contrast, spinal ganglia and sympathetic ganglia, tissues in which GABA uptake is restricted to glial cells, did not accumulate [aH] ACHC (Fig. 1). In both types of ganglia the tissue: medium ratios reached only 0.7 after 60 min incubations, a value indicating accumulation only in the extracellular water. The rat retina, in which GABA uptake is also predominantly glial, was found to accumulate about the same amount of [3H] ACHC when incubated at 37 C as the frog retina at 25 C (Fig. 1). This result is not, at first sight, consistent with ACHC having affinity only for the neuronal GABA transport system, but it is