The Effect of Training on Erythrocyte Energy Status and Plasma Purine Metabolites in Athletes

Abstract

This study aimed to assess the changes in red blood cell (RBC) energy status and plasma purine metabolites concentration over a one-year training cycle in endurance-trained (EN; n = 11, 20-26 years), and sprint-trained (SP; n = 11, 20-30 years) competitive athletes in comparison to recreationally-trained individuals (RE; n = 11, 20-26 years). Somatic, physiological, and biochemical variables were measured in four training phases differing in exercise load profile: transition, general, specific, and competition. Significantly highest values of RBC adenylate energy charge (AEC; p ≤ 0.001), ATP-to-ADP and ADP-to-AMP ratios (p ≤ 0.05), and plasma levels of adenosine (Ado; p ≤ 0.05) were noted in the competition phase in the EN and SP, but not in the RE group. Significantly lowest plasma levels of adenosine diphosphate (ADP; p ≤ 0.05), adenosine monophosphate (AMP; p ≤ 0.001), inosine (Ino; p ≤ 0.001), and hypoxanthine (Hx; p ≤ 0.001) accompanied by higher erythrocyte hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity (p ≤ 0.001), were observed in the competition phase in both athletic groups. No significant alterations were found in the erythrocyte concentration of guanine nucleotides in any group. In conclusion, periodized training of competitive athletes' results in a favorable adaptation of RBC metabolism. The observed changes cover improved RBC energy status (increased AEC and ATP/ADP ratio) and reduced purine loss with more efficient erythrocyte purine pool recovery (increased HGPRT activity and plasma levels of Ado; decreased Hx and Ino concentration).Metabolites 2020, 10, 5 2 of 15 to sedentary humans, besides increased erythropoiesis, there is also observed enhanced erythrocyte turnover and an increase in the number of young red blood cells [2,3].The RBCs' vitality, resilience, and functioning rely on their energy metabolism, mainly glycolysis, which is the only source of adenosine triphosphate (ATP) in RBC [7]. Since ATP resynthesis involves multistep metabolic pathways, the amount of RBC energy resources is usually described by the concentration of ATP, adenosine triphosphate/adenosine diphosphate ratio (ATP/ADP), and the adenylate energy charge (AEC) [8].There are scant studies reporting changes in purine nucleotide catabolite concentration in human and animal erythrocytes in response to single bouts of exercise [3,[9][10][11]. The results obtained from humans suggest that both maximum- [3,9] and moderate-intensity [10] exercise do not significantly affect the total adenylate and guanylate concentration, while adenine (but not guanine) nucleotide concentration in the adenylate pool considerably changes. A substantial post-exercise decrease in adenosine diphosphate (ADP) and adenosine monophosphate (AMP) concentration leads to an increase in ATP/ADP ratio, ADP/AMP ratio, and AEC. These observations are in line with data derived from animals [11].The research conducted so far demonstrated that there were significant differences between trained and sedentary individuals in erythrocyte energetics ...

Changes in the Concentration of Purine and Pyridine as a Response to Single Whole-Body Cryostimulation

“…This explains the presence of lower plasma hypoxanthine concentration, which is probably used as substrates in ATP resynthesis ( López-Cruz et al, 2016 ). Also, in response to frequent episodes of hypoxia (high intensity training), an increase in HGPRT activity in muscles and erythrocytes explains the significantly lower plasma concentration of inosine and hypoxanthine at rest and after intense physical effort ( Hellsten-Westing et al, 1993 ; Dudzinska et al, 2018 ; Pospieszna et al, 2019 ). However, if more efficient purine recycling may be one of the possible reasons explaining the decrease in blood concentration of inosine and hypoxanthine, it is still doubtful to what extent this mechanism explains the changes in inosine and hypoxanthine concentrations after the exposure to extremely low temperatures.…”

“…Erythrocytes were washed with buffered 0.9% NaCl solution and centrifuged (1,000 × g , 5 min, 4°C). The nucleotide concentration was determined in washed erythrocytes and expressed in relation to the volume of erythrocytes as previously described ( Pospieszna et al, 2019 ; Rodziewicz et al, 2020 ).…”

“…The concentrations of purine and pyridine, which were analyzed, were determined by high-performance liquid chromatography (HPLC). It was done in accordance with the method described in detail by Smolenski et al (1990) and used by us ( Dudzinska et al, 2018 ; Pospieszna et al, 2019 ).…”

Plasma Concentration of Irisin and Brain-Derived-Neurotrophic Factor and Their Association With the Level of Erythrocyte Adenine Nucleotides in Response to Long-Term Endurance Training at Rest and After a Single Bout of Exercise

“…The purine nucleotide (ATP, ADP, AMP, and IMP) concentrations were assessed in erythrocytes using high-performance liquid chromatography with UV-VIS detection (Merck-Hitachi/Agilent, Tokyo, Japan/Santa Clara, CA, United States) according to the method used and described in details by Smolenski et al (1990) and Pospieszna et al (2019) . To determine ATP, ADP, and AMP levels, the aliquots of 100 μL were injected into the sample loop.…”

“…Previous data showed that also BDNF regulates cellular bioenergetics and increases neuronal ATP production (Cheng et al, 2012). Pospieszna et al (2019) demonstrated that in competitive athletes, an increment in the RBC energy status occurred across an annual training cycle, as assessed by the increments in AEC and ATP/ADP and ADP/AMP ratios. This suggests that red blood cell metabolism adjusts to increased physical requirements of consecutive training phases.…”