Cavan K R, MacDonald E J, Smith T K
Department of Nutritional Sciences, University of Guelph, Ontario, Canada.
J Nutr. 1988 Jul;118(7):901-7. doi: 10.1093/jn/118.7.901.
Experiments were conducted to determine the potential for overcoming T-2 toxin-induced changes in brain neurotransmitter concentrations through dietary manipulation. Rats were fed either a tryptophan-deficient, gelatin-based diet or the same diet supplemented with a mixture of large neutral amino acids for 4 d. Rats were then dosed with 0 or 2.0 mg T-2 toxin/kg body weight and killed 4, 8 or 12 h after dosing. The large neutral amino acid supplements successfully reduced brain concentrations of tryptophan and serotonin in control rats, but this was not enough to overcome the acute effects seen in T-2 toxin-treated rats. A further experiment was then conducted to monitor the effect of T-2 toxin on the ratio of free to protein-bound tryptophan in plasma. Total plasma tryptophan increased in T-2 toxin-treated rats, although there were no significant differences in the ratio of free to protein-bound tryptophan. A final experiment was conducted to determine the specificity of the T-2 toxin effect on concentrations of plasma amino acids. Concentrations of amino acids that use the large neutral amino acid transport system into the brain were higher in T-2 toxin-treated animals. The only other amino acid that had a higher concentration was arginine. It was concluded that acute doses of T-2 toxin may selectively alter membrane transport of amino acids.
开展实验以确定通过饮食调控克服T-2毒素引起的大脑神经递质浓度变化的可能性。给大鼠喂食缺乏色氨酸的明胶基饮食或添加了大中性氨基酸混合物的相同饮食，持续4天。然后给大鼠分别注射0或2.0毫克/千克体重的T-2毒素，并在注射后4、8或12小时处死。大中性氨基酸补充剂成功降低了对照大鼠大脑中色氨酸和5-羟色胺的浓度，但这不足以克服T-2毒素处理大鼠中观察到的急性效应。随后进行了进一步实验，以监测T-2毒素对血浆中游离色氨酸与蛋白质结合色氨酸比例的影响。T-2毒素处理的大鼠血浆总色氨酸增加，尽管游离色氨酸与蛋白质结合色氨酸的比例没有显著差异。进行了最后一项实验，以确定T-2毒素对血浆氨基酸浓度影响的特异性。使用大中性氨基酸转运系统进入大脑的氨基酸在T-2毒素处理的动物中浓度更高。唯一浓度较高的其他氨基酸是精氨酸。得出的结论是，急性剂量的T-2毒素可能会选择性地改变氨基酸的膜转运。
