SEROTONIN SYNTHESIS AND RELEASE IN BRAIN-SLICES - INDEPENDENCE OF TRYPTOPHAN
SEROTONIN SYNTHESIS AND RELEASE IN BRAIN-SLICES - INDEPENDENCE OF TRYPTOPHAN
复制标题
DOI：
10.1016/0006-8993(79)90580-8
复制
发表时间：
1979-01-01
期刊：
影响因子：
2.9
通讯作者：
KIZER, JS
中科院分区：
文献类型：
--
作者：
ELKS, ML;YOUNGBLOOD, WW;KIZER, JS
研究了底物利用率在脑片5-羟色胺释放和合成调节中的作用。电场去极化的脑切片刺激的合成和释放的5-羟色胺的细胞内色氨酸浓度的变化的情况下，在没有色氨酸的情况下，在孵育浴，并在没有总色氨酸摄取的变化。电刺激降低了切片合成5-羟色胺所需的色氨酸的表观Km。得出了若干结论。脑切片中5-羟色胺的释放和合成速率可能独立于组织色氨酸浓度或色氨酸摄取而增加。在暴露于帕吉林或完全不暴露于帕吉林的组织中，5-羟色胺的合成速率几乎没有差异。阻断单胺氧化酶的帕吉林似乎给估计的5-羟色胺的合成率，这是来自[3 H]-色氨酸掺入的估计。新合成的血清素优先释放。只有在用帕吉林预处理的组织中，色氨酸浓度的增加才能增加5-HT [羟色胺]的可释放库。电去极化可能会变构激活色氨酸羟化酶;这种效应可以通过组织的均质化来模拟。
The role of substrate availability in the regulation of the release and synthesis of serotonin by brain slices was investigated. Electrical field depolarization of the brain slices stimulated the synthesis and release of serotonin in the absence of changes in intracellular tryptophan concentration, in the absence of tryptophan in the incubation bath, and in the absence of changes in total tryptophan uptake. Electrical stimulation decreased the apparent Km for tryptophan required for synthesis of serotonin by the slices. Several conclusions were drawn. Rates of serotonin release and synthesis in brain slices may increase independently of the tissue tryptophan concentration or tryptophan uptake. There is little difference in the synthetic rate of serotonin in tissues exposed to pargyline or not at all. Blockade of monoamine oxidase by pargyline appears to give estimates of the synthetic rates of serotonin which are comparable to estimates derived from [3H]-tryptophan incorporation. Newly synthesized serotonin is preferentially released. Only in tissue pretreated with pargyline do increasing concentrations of tryptophan increase the releasable pool of 5-HT [hydroxytryptamine]. Electrical depolarization may allosterically activate tryptophan hydroxylase; an effect which may be mimicked by homogenization of the tissue.