Changes in plasma and urinary taurine and amino acids in runners immediately and 24 h after a marathon

Abstract

Changes in urinary and plasma taurine and amino acids have been evaluated in trained runners competing in the Rotterdam Marathon, 1998, both immediately after completing the event and 24h after recovery. There were significant changes in the urinary amino acids excretion, the majority showing a significant decrease both immediately at the completion of the Marathon and after 24h recovery. In contrast urinary taurine excretion increased immediately post Marathon, although not significantly as the range of results was wide. Such changes in urinary taurine correlated with percentage changes in plasma creatine kinase both immediately post race, (r = 0.972, P < 0.001), and 24h later (r = 0.872, P < 0.001), possibly indicating that the source of the taurine was muscle. Significant correlations between the individual values for urinary and plasma amino acids in all of the athletes were calculated for taurine (r = 0.528), glycine (r = 0.853), threonine (r = 0.749), alanine (r = 0.747), serine (r = 0.620), glutamine (0.614), arginine (r = 0.507), histidine (r = 0.470) and valine (r = 0.486). Changes in the mean plasma concentrations of amino acids were comparable to our previously published data (Ward et al., 1999) the majority showing significant decreases immediately and 24h post Marathon, such an adaptation being due primarily to their utilisation for gluconeogenesis. However, in contrast, the mean taurine concentrations were significantly elevated both post race, P < 0.01 and after 24h, P < 0.05. The physiological response by the muscle to exhaustive exercise, particularly with regard to changes in plasma and urinary taurine concentrations remain to be elucidated, but is probably related to muscle function impairment. The increase in taurine urinary excretion could be used as an indicator of muscle damage occurring during exhaustive exercise. Whether taurine supplementation would minimise such changes is an interesting scientific question and merits investigation.

Role of taurine in osmoregulation during endurance exercise

“…Subsequently, an RVD process would occur with the release of ions (mostly potassium and chloride) and other osmotically active solutes including taurine from the cell (Lang et al 1998). The present study confirms that the intracellular osmolytes potassium, chlorine and taurine are extruded from the muscle during exercise (Cuisinier et al 2001;Graham et al 1991Graham et al , 1995, due to an RVD. Thus, the release of taurine and potassium should be higher when the gradient of osmolality is greater (i.e.…”

“…In man, plasma taurine concentration ranges from 29 to 49 lM (Cuisinier et al 2001;Gutierrez et al 1999;Maggs et al 1995), and from 165 to 199 lM in the interstitial muscle space (Blomstrand and Saltin 1999;Gutierrez et al 1999). By contrast, the intracellular taurine level in the vastus lateralis muscle is 50 and 62 mmolAE(kg dry weight) -1 in sedentary subjects and endurance-trained men, respectively (Blomstrand and Saltin 1999;Graham et al 1995).…”

“…Thus, plasma taurine changes cannot originate from blood cells, although the latter appears to play a buffering role by attenuating plasma taurine increase. Cuisinier et al (2001) showed that taurine concentration in cell-rich plasma was not modified after a marathon run. It is therefore likely that the erythrocytes are responsible for the taurine content increase in blood cellular elements.…”

“…For example, studies of femoral arteriovenous differences suggest that contracting muscles release taurine (Graham et al 1991(Graham et al , 1995, while repeated stimulations of isolated mouse muscles induce the release of taurine into the bathing solution (Cuisinier, unpublished observations). Therefore, the increase in plasma taurine content observed during endurance events such as a marathon or a 100-km run was attributed to the release of muscle taurine (Cuisinier et al 2001;Ward et al 1999). However, the physiological importance of this taurine shift has not been investigated previously.…”

Exercise-induced changes in amino acid levels in skeletal muscle and plasma

“…Ward et al 78) showed that a 90-min run on a treadmill, a full marathon, and a 100-km run increased plasma taurine levels by 19%, 77%, and 36%, respectively. Furthermore, Cuisinier et al 79) confirmed significantly higher levels of plasma taurine in the first 24-hour period after a full marathon compared with pre-marathon levels. In good agreement with these findings, we also confirmed significant increases in plasma taurine levels induced by prolonged exercise 80) .…”