HIGH-AFFINITY TRANSPORT OF GAMMA-AMINOBUTYRIC-ACID, GLYCINE, TAURINE, L-ASPARTIC ACID, AND L-GLUTAMIC ACID IN SYNAPTOSOMAL (P2) TISSUE - A KINETIC AND SUBSTRATE-SPECIFICITY ANALYSIS
HIGH-AFFINITY TRANSPORT OF GAMMA-AMINOBUTYRIC-ACID, GLYCINE, TAURINE, L-ASPARTIC ACID, AND L-GLUTAMIC ACID IN SYNAPTOSOMAL (P2) TISSUE - A KINETIC AND SUBSTRATE-SPECIFICITY ANALYSIS
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DOI：
10.1111/j.1471-4159.1987.tb05747.x
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发表时间：
1987-06-01
影响因子：
4.7
通讯作者：
LAJTHA, A
中科院分区：
文献类型：
--
作者：
DEBLER, EA;LAJTHA, A
在皮质P2部分中，[14 C] γ-氨基丁酸（[14 C]GABA）、[14 C]甘氨酸、[14 C]牛磺酸和[14 C]谷氨酸和[14 C]天冬氨酸通过四种独立的高亲和力转运系统转运，L-谷氨酸和L-天冬氨酸通过共同的系统转运。皮质突触体组织中的GABA转运通过一个高亲和力系统发生，没有第二个低亲和力转运系统可检测到。只有一个高亲和力系统的天冬氨酸/谷氨酸的运输观察，与GABA的运输，没有低亲和力的运输是可检测的。在摄取牛磺酸和甘氨酸（大脑皮质和脑桥-延髓-脊髓）的高和低亲和力的运输过程中，可以检测到。高亲和力GABA和高亲和力牛磺酸转运类别表现出一些重叠，GABA转运系统更具特异性，并且具有高得多的Vmax值。高亲和力GABA转运与高亲和力甘氨酸或高亲和力天冬氨酸/谷氨酸转运类没有重叠，事实上，它们在抑制谱中表现出一定的负相关性。高亲和力皮质甘氨酸转运和高亲和力皮质牛磺酸和天冬氨酸/谷氨酸转运的抑制曲线也没有显示出显着的正相关关系。高亲和力甘氨酸转运在大脑皮质和脑桥-延髓-脊髓中的抑制曲线显示彼此显著正相关;然而，脑桥-延髓-脊髓中的高亲和力甘氨酸摄取比大脑皮质中的高亲和力甘氨酸摄取更具特异性。高亲和力牛磺酸转运的抑制曲线与天冬氨酸/谷氨酸转运类呈非显著负相关。
In a cortical P2 fraction, [14C].gamma.-aminobutyric acid ([14C]GABA), [14C]glycine, [14C]taurine, and [14C]glutamic and [14C]aspartic acids are transported by four separate high-affinity transport systems with L-glutamic acid and L-aspartic acid transported by a common system. GABA transport in cortical synaptosomal tissue occurs by one high-affinity system, with no second, low-affinity, transport system detectable. Only one high-affinity system is observed for the transport of aspartic/glutamic acids; as with GABA transport, no low-affinity transport is detectable. In the uptake of taurine and glycine (cerebral cortex and pons-medulla-spinal cord) both high- and low-affinity transport processes could be detected. The high-affinity GABA and high-affinity taurine transport classes exhibit some overlap, with the GABA transport system being more specific and having a much higher Vmax value. High-affinity GABA transport exhibits no overlap with either the high-affinity glycine or the high-affinity aspartic/glutamic acid transport class, and in fact they demonstrate somewhat negative correlations in inhibition profiles. The inhibition profiles of high-affinity cortical glycine transport and those of high-affinity cortical taurine and aspartic/glutamic acid transport also show no significant positive relationship. The inhibition profiles of high-affinity glycine transport in the cerebral cortex and in the pons-medulla-spinal cord show a significant positive correlation with each other; however, high-affinity glycine uptake in the pons-medulla-spinal cord is more specific than that in the cerebral cortex. The inhibition profile of high-affinity taurine transport exhibits a nonsignificant negative correlation with that of the aspartic/glutamic acid transport class.