Effect of 4-week physical exercises on tryptophan, kynurenine and kynurenic acid content in human sweat

Abstract

The aim of the study was the detection of TRP, kynurenine (KYN), and kynurenic acid (KYNA) in human sweat, and determining whether physical activity affects their content in this secrete. Two different methods were used simultaneously—collection of sweat by means of an absorption pad from the inter scapular region, and collection of a drop of sweat from the region of the forehead. Quantitative determinations of TRP, KYN and KYNA were performed using high performance liquid chromatography with ultraviolet and fluorescence detection. Determinations of sodium was carried out by the method of inductively coupled plasma collision/reaction cell ionization mass spectrophotometry. It was found that physical exercises evoked a decrease in the amount of KYN, and an increase in the amount of KYNA in sweat recorded on day 14, but not on day 28 of training. It appears that physical exercises result in a long-term increase in the kynurenine transaminase activity responsible for the formation of KYNA from KYN. Based on this results, it can be suggested that measurement of TRP, KYN and KYNA in sweat may have diagnostic potential and may help to establish an exercise regime appropriate for the age, gender and health status of rehabilitation patients.

Kynurenic Acid Acts as a Signaling Molecule Regulating Energy Expenditure and Is Closely Associated With Metabolic Diseases

“…Regarding the effect of long-term exercise on KYNA, a recent study of 4-week physical exercises on human found that physical exercises promote an increase in the amount of KYNA in sweat on day 14. The KYNA level returned to baseline on day 28 ( 66 ). Additionally, inhibition of KYATs reduces myotube oxidative capacity and exercise performance in mice ( 67 ).…”

The Organ of Vision and the Stomatognathic System—Review of Association Studies and Evidence-Based Discussion

“…The reaction is catalyzed by tryptophan-2,3-dioxygenase (TDO) or indoleamine-2,3-dioxygenases 1 and 2 (IDO). TDO is a constitutive enzyme present mainly in the liver [ 66 ]. KYNA is enzymatically produced from a key intermediate compound in the tryptophan catabolic pathway, KYN [ 67 ].…”

“…KYNA is enzymatically produced from a key intermediate compound in the tryptophan catabolic pathway, KYN [ 67 ]. KYN and its metabolites, collectively known as kynurenines, exhibit diverse biological activities [ 66 ]. Initially, both quinolinic acid and KYNA, a glutamate agonist and antagonist, respectively, were shown to be involved in the control of neurotransmission, neuronal cell membrane excitability, and neurodegeneration [ 66 , 68 ].…”

“…KYN and its metabolites, collectively known as kynurenines, exhibit diverse biological activities [ 66 ]. Initially, both quinolinic acid and KYNA, a glutamate agonist and antagonist, respectively, were shown to be involved in the control of neurotransmission, neuronal cell membrane excitability, and neurodegeneration [ 66 , 68 ]. It has been shown that KYNA can protect neurons from excitotoxic damage caused by quinolinic acid [ 69 , 70 ].…”

“…It is now broadly believed that physical activity may have beneficial outcomes on the central nervous system, as a result of reducing the amount of circulating KYN available for further metabolism in the brain [ 84 , 85 ]. Based on numerous studies, the link between exercise-induced changes in peripheral kynurenine homeostasis and brain function appears to be indisputable [ 66 , 85 , 86 , 87 ]. It has also been demonstrated that skeletal muscle is a heterogeneous tissue composed of cell types with different metabolic profiles, including KYN metabolism, which has implications for KYN-modulating mechanisms [ 88 ].…”