Acute tryptophan and serotonin depletion using an optimized tryptophan-free protein-carbohydrate mixture in the adult rat
Acute tryptophan and serotonin depletion using an optimized tryptophan-free protein-carbohydrate mixture in the adult rat
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DOI：
10.1016/s0197-0186(03)00102-5
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发表时间：
2004-01-01
影响因子：
4.2
通讯作者：
Deutz, NEP
中科院分区：
文献类型：
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作者：
Lieben, CKJ;Blokland, A;Deutz, NEP
与人类相反，色氨酸（TRP）-游离氨基酸（AA）混合物仅导致成年大鼠血浆TRP水平中度耗竭。在这项研究中，我们评估了成年雄性Wistar大鼠急性给药不含TRP的蛋白质-碳水化合物营养混合物的影响。在首次给药后2和4 h开始检查血浆氨基酸水平。此外，还测定了纹状体、海马和皮质内氨基酸、5-羟色胺（5-HT）、多巴胺（DA）及其代谢产物5-羟基吲哚乙酸（5-HIAA）和3，4-二羟基苯乙酸（DOPAC）的含量。在TRP耗尽的动物中，TRP/SigmaLNAA比率（LNAA：大中性氨基酸）在首次口服给药后2和4小时显著降低（分别降低71%和78%）。治疗后4小时，中央TRP和5-HT浓度下降了50%。在用补充有TRP的营养混合物处理的组中，外周和中央TRP水平均恢复到基础值。令人惊讶的是，酪氨酸水平也降低后，口服给药的蛋白质-碳水化合物的混合物，而不影响中央DA浓度。总之，不含TRP的蛋白质-碳水化合物营养混合物似乎是显著降低成年大鼠血浆和中枢TRP水平的有效工具。(C)2003爱思唯尔科技有限公司版权所有。
In contrast to humans, a tryptophan (TRP)-free amino acid (AA) mixture only leads to moderate depletion in plasma TRP levels in adult rats. In this study we evaluated the effects of an acute administration of a TRP-free protein-carbohydrate nutritional mixture in adult male Wistar rats. Plasma amino acid levels were examined at 2 and 4 h starting after the first administration. Furthermore, the concentrations of amino acid, serotonin (5-HT), dopamine (DA) and their metabolite (5-hydroxyindolacetic acid (5-HIAA) and 3,4-dihydroxyphenylacetic acid (DOPAC), respectively) were measured within the striatum, hippocampus and cortex. In the TRP depleted animals, the TRP/SigmaLNAA ratio (LNAA: large neutral amino acids) was substantial decreased at 2 and 4 h after the first administration of the oral administration (by 71 and 78%, respectively). Four hours after treatment central TRP and 5-HT concentrations were decreased by 50%. Both peripheral and central TRP levels returned to basal values in the group treated with the nutritional mixture supplemented with TRP. Surprisingly, tyrosine levels were also reduced after oral administration of the protein-carbohydrate mixture without affecting central DA concentrations. In conclusion, the TRP-free protein-carbohydrate nutritional mixture appears to be an efficient tool to substantially reduce plasma and central TRP levels in adult rat. (C) 2003 Elsevier Science Ltd. All rights reserved.