Tryptophan metabolites regulate a variety of physiological processes, and their downstream metabolites enter the kynurenine pathway. Age-related changes of metabolites and activities of associated enzymes in this pathway are suggestable and would be potential intervention targets. Blood levels of serum tryptophan metabolites in C57BL/6 mice of different ages, ranging from 6 weeks to 10 months, were assessed using high-performance liquid chromatography, and the enzyme activities for each metabolic step were estimated using the ratio of appropriate metabolite levels. Mice were subjected to voluntary chronic aerobic exercise or high-fat diet to assess their ability to rescue age-related alterations in the kynurenine pathway. The ratio of serum kynurenic acid (KYNA) to 3-hydroxylkynurenine (3-HK) decreased with advancing age. Voluntary chronic aerobic exercise and high-fat diet rescued the decreased KYNA/3-HK ratio in the 6-month-old and 8-month-old mice groups. Tryptophan metabolites and their associated enzyme activities were significantly altered during aging, and the KYNA/3-HK ratio was a meaningful indicator of aging. Exercise and high-fat diet could potentially recover the reduction of the KYNA/3-HK ratio in the elderly.

中文翻译：

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高脂饮食和自愿性慢性有氧运动可恢复沿Kureurenine途径老化的色氨酸代谢产物的变化水平。

色氨酸代谢物调节多种生理过程，其下游代谢物进入犬尿氨酸途径。该途径中代谢物和相关酶活性的年龄相关变化是可预见的，并将成为潜在的干预目标。使用高效液相色谱法评估6周至10个月不等年龄的C57BL / 6小鼠血清色氨酸代谢产物的血药水平，并使用适当代谢产物水平的比率估算每个代谢步骤的酶活性。对小鼠进行自愿的有氧运动或高脂饮食，以评估其挽救犬尿氨酸途径中与年龄有关的改变的能力。随着年龄的增长，血清尿酸（KYNA）与3-羟基尿嘧啶（3-HK）的比例降低。自愿的长期有氧运动和高脂饮食可以挽救6个月大和8个月大的小鼠组的KYNA / 3-HK比值降低。色氨酸代谢产物及其相关的酶活性在衰老过程中发生了显着变化，KYNA / 3-HK比值是衰老的有意义的指标。运动和高脂饮食有可能使老年人的KYNA / 3-HK比值降低。