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Role of Tyrosine Isomers in Acute and Chronic Diseases Leading to Oxidative Stress - A Review

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ABSTRACT

Oxidative stress plays a major role in the pathogenesis of a variety of acute and chronic diseases. Measurement of the oxidative stress-related end products may be performed, e.g. that of structural isomers of the physiological para-tyrosine, namely meta- and ortho-tyrosine, that are oxidized derivatives of phenylalanine. Recent data suggest that in sepsis, serum level of meta-tyrosine increases, which peaks on the 2nd and 3rd days (p<0.05 vs. controls), and the kinetics follows the intensity of the systemic inflammation correlating with serum procalcitonin levels. In a similar study subset, urinary meta-tyrosine excretion correlated with both need of daily insulin dose and the insulin-glucose product in non-diabetic septic cases (p<0.01 for both). Using linear regression model, meta-tyrosine excretion, urinary meta-tyrosine/para-tyrosine, urinary ortho-tyrosine/para-tyrosine and urinary (meta- + ortho-tyrosine)/para-tyrosine proved to be markers of carbohydrate homeostasis.

In a chronic rodent model, we tried to compensate the abnormal tyrosine isomers using para-tyrosine, the physiological amino acid. Rats were fed a standard high cholesterol-diet, and were given para-tyrosine or vehicle orally. High-cholesterol feeding lead to a significant increase in aortic wall meta-tyrosine content and a decreased vasorelaxation of the aorta to insulin and the glucagon-like peptide-1 analogue, liraglutide, that both could be prevented by administration of para-tyrosine.

Concluding, these data suggest that meta- and ortho-tyrosine are potential markers of oxidative stress in acute diseases related to oxidative stress, and may also interfere with insulin action in septic humans. Competition of meta- and ortho-tyrosine by supplementation of para-tyrosine may exert a protective role in oxidative stress-related diseases.

No MeSH data available.


Urinary (A) meta-tyrosine/creatinine, (B) ortho-tyrosine/creatinine and (C) para-tyrosine/creatinine ratio in septic patients. Data are expressed as median, inter-quartile range (IQR; standard 25th-75th percentile) and 5th and 95th confidence interval. Asterisks indicate statistical differences within the septic group compared to day 1. (*: p<0.05; **: p<0.01; ***: p<0.001). The “#” symbols show significant differences between patients and controls (#: p<0.05; ##: p<0.01; ###: p<0.001). Urinary meta-tyrosine/creatinine ratios had a decreasing tendency (p=0.018), while urinary para-tyrosine/creatinine ratios showed a marked increase (p=0.001). Reproduced with permission of Maney Publishing Ltd. from Szélig et al. Redox Report 2015. Jul. 20 [53].
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Figure 7: Urinary (A) meta-tyrosine/creatinine, (B) ortho-tyrosine/creatinine and (C) para-tyrosine/creatinine ratio in septic patients. Data are expressed as median, inter-quartile range (IQR; standard 25th-75th percentile) and 5th and 95th confidence interval. Asterisks indicate statistical differences within the septic group compared to day 1. (*: p<0.05; **: p<0.01; ***: p<0.001). The “#” symbols show significant differences between patients and controls (#: p<0.05; ##: p<0.01; ###: p<0.001). Urinary meta-tyrosine/creatinine ratios had a decreasing tendency (p=0.018), while urinary para-tyrosine/creatinine ratios showed a marked increase (p=0.001). Reproduced with permission of Maney Publishing Ltd. from Szélig et al. Redox Report 2015. Jul. 20 [53].


Role of Tyrosine Isomers in Acute and Chronic Diseases Leading to Oxidative Stress - A Review
Urinary (A) meta-tyrosine/creatinine, (B) ortho-tyrosine/creatinine and (C) para-tyrosine/creatinine ratio in septic patients. Data are expressed as median, inter-quartile range (IQR; standard 25th-75th percentile) and 5th and 95th confidence interval. Asterisks indicate statistical differences within the septic group compared to day 1. (*: p<0.05; **: p<0.01; ***: p<0.001). The “#” symbols show significant differences between patients and controls (#: p<0.05; ##: p<0.01; ###: p<0.001). Urinary meta-tyrosine/creatinine ratios had a decreasing tendency (p=0.018), while urinary para-tyrosine/creatinine ratios showed a marked increase (p=0.001). Reproduced with permission of Maney Publishing Ltd. from Szélig et al. Redox Report 2015. Jul. 20 [53].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4997921&req=5

Figure 7: Urinary (A) meta-tyrosine/creatinine, (B) ortho-tyrosine/creatinine and (C) para-tyrosine/creatinine ratio in septic patients. Data are expressed as median, inter-quartile range (IQR; standard 25th-75th percentile) and 5th and 95th confidence interval. Asterisks indicate statistical differences within the septic group compared to day 1. (*: p<0.05; **: p<0.01; ***: p<0.001). The “#” symbols show significant differences between patients and controls (#: p<0.05; ##: p<0.01; ###: p<0.001). Urinary meta-tyrosine/creatinine ratios had a decreasing tendency (p=0.018), while urinary para-tyrosine/creatinine ratios showed a marked increase (p=0.001). Reproduced with permission of Maney Publishing Ltd. from Szélig et al. Redox Report 2015. Jul. 20 [53].

View Article: PubMed Central - PubMed

ABSTRACT

Oxidative stress plays a major role in the pathogenesis of a variety of acute and chronic diseases. Measurement of the oxidative stress-related end products may be performed, e.g. that of structural isomers of the physiological para-tyrosine, namely meta- and ortho-tyrosine, that are oxidized derivatives of phenylalanine. Recent data suggest that in sepsis, serum level of meta-tyrosine increases, which peaks on the 2nd and 3rd days (p&lt;0.05 vs. controls), and the kinetics follows the intensity of the systemic inflammation correlating with serum procalcitonin levels. In a similar study subset, urinary meta-tyrosine excretion correlated with both need of daily insulin dose and the insulin-glucose product in non-diabetic septic cases (p&lt;0.01 for both). Using linear regression model, meta-tyrosine excretion, urinary meta-tyrosine/para-tyrosine, urinary ortho-tyrosine/para-tyrosine and urinary (meta- + ortho-tyrosine)/para-tyrosine proved to be markers of carbohydrate homeostasis.

In a chronic rodent model, we tried to compensate the abnormal tyrosine isomers using para-tyrosine, the physiological amino acid. Rats were fed a standard high cholesterol-diet, and were given para-tyrosine or vehicle orally. High-cholesterol feeding lead to a significant increase in aortic wall meta-tyrosine content and a decreased vasorelaxation of the aorta to insulin and the glucagon-like peptide-1 analogue, liraglutide, that both could be prevented by administration of para-tyrosine.

Concluding, these data suggest that meta- and ortho-tyrosine are potential markers of oxidative stress in acute diseases related to oxidative stress, and may also interfere with insulin action in septic humans. Competition of meta- and ortho-tyrosine by supplementation of para-tyrosine may exert a protective role in oxidative stress-related diseases.

No MeSH data available.