Purpose

Serious burn injury leads to oxidative stress resulting in production of meta- and ortho-tyrosine, while para-tyrosine is the physiological isoform. Our aim was to investigate the metabolism of these tyrosine isoforms following major burn injury.

Methods

Fifteen patients requiring intensive care were followed for 5 consecutive days after major burn injury. Serum and urine concentrations of para-, meta-, and ortho-tyrosine were measured with high performance liquid chromatography. Fifteen healthy matching individuals were invited as control group.

Results

Median serum concentration of normal isoform para-tyrosine decreased in burned patients between days 2 and 5 (p < 0.01). Mean meta-, and ortho-tyrosine levels were significantly higher in patients compared to controls in the same time period (p < 0.05). Renal excretion of para-tyrosine increased significantly in our observation period (p < 0.01).

Conclusions

Pathologic isoforms of tyrosine accumulate in serum meanwhile the level of normal isoform decreases possibly due to belated enhanced renal excretion or, to decreased synthesis after major burn injury.

中文翻译：

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烧伤患者对位、间位和邻位酪氨酸随时间的变化。

目的

严重的烧伤会导致氧化应激，导致产生间位和邻位酪氨酸，而对位酪氨酸是生理异构体。我们的目的是研究这些酪氨酸亚型在严重烧伤后的代谢。

方法

15 名需要重症监护的患者在严重烧伤后连续 5 天接受随访。用高效液相色谱法测量对-、间-和邻-酪氨酸的血清和尿液浓度。邀请15名健康匹配个体作为对照组。

结果

烧伤患者的正常同工型副酪氨酸血清浓度中位数在第 2 天和第 5 天之间下降（p < 0.01）。与同期对照组相比，患者的平均间位和邻位酪氨酸水平显着更高（p < 0.05）。在我们的观察期内，对酪氨酸的肾脏排泄显着增加（p < 0.01）。

结论

酪氨酸的病理异构体在血清中积累，同时正常异构体的水平降低可能是由于肾排泄延迟增加或严重烧伤后合成减少。