Sharma R P, Coulombe R A
Food Chem Toxicol. 1987 Aug;25(8):565-8. doi: 10.1016/0278-6915(87)90015-9.
Following a finding that single doses (approximating to average intakes and to potential 'over-use') of aspartame administered orally to mice caused significant increases in norepinephrine and dopamine concentrations in various brain regions, the effect of repeated exposure to aspartame was studied. Male CD-1 mice were given a daily oral dose of 0, 13, 133 or 650 mg/kg for 30 days and 1 day after the last dose the animals were decapitated and their brain regions were quickly isolated. Analyses of the different regions for catecholamine and indoleamine neurotransmitters and their major metabolites indicated that the increases in adrenergic chemicals observed shortly after a single exposure were not apparent after repeated dosing. In contrast, concentrations of serotonin and its metabolite, 5-hydroxyindoleacetic acid, were decreased in several regions. An increased supply of phenylalanine may be responsible for a decrease in tryptophan uptake by the brain tissue or for a depression in tryptophan conversion to serotonin.
在发现给小鼠口服单剂量阿斯巴甜（接近平均摄入量和潜在的“过量使用”剂量）会导致其多个脑区去甲肾上腺素和多巴胺浓度显著升高后，研究了重复接触阿斯巴甜的影响。雄性CD-1小鼠连续30天每天口服0、13、133或650毫克/千克的剂量，在最后一剂后的第1天，将动物断头并迅速分离其脑区。对不同脑区的儿茶酚胺和吲哚胺神经递质及其主要代谢产物的分析表明，单次接触后不久观察到的肾上腺素能化学物质的增加在重复给药后并不明显。相反，血清素及其代谢产物5-羟吲哚乙酸在几个脑区的浓度降低。苯丙氨酸供应增加可能是导致脑组织对色氨酸摄取减少或色氨酸转化为血清素受到抑制的原因。
