Effects of Ultramarathon Running on Mitochondrial Function of Platelets and Oxidative Stress Parameters: A Pilot Study

Abstract

Only a few studies have evaluated changes in mitochondrial function and oxidative stress associated with ultramarathon running. Invasive biopsies are needed to assess mitochondrial function of skeletal muscle, which may not be well tolerated by some individuals. Platelets (PLTs) as a metabolically highly active and homogenous cell population were suggested as a potentially valuable surrogate to investigate mitochondrial function. Thus, this study was aimed to evaluate mitochondrial function of PLTs and its association with individual race performance and markers of oxidative stress, muscle damage and renal dysfunction. Race performance and mitochondrial function (high-resolution respirometry, HRR) of PLTs using different substrates inducing ROUTINE, LEAK, N-pathway control state (Complex I linked oxidative phosphorylation; CI, OXPHOS), NS-pathway control state (CI + II linked OXPHOS and electron transfer pathway; ET), S-pathway control state (CII linked ET) as well as parameters of oxidative stress and antioxidant capacity, and markers of muscle and renal injury were assessed in eight male ultramarathon runners (26–45 years) before, immediately after and 24 h after an ultramarathon race (PRE, POST, and REC). Ultramarathon running induced an increase in LEAK O2 flux of PLT mitochondria and slight, largely non-significant changes in the oxidant/antioxidant balance. Levels of creatine kinase (CK), lactate dehydrogenase (LDH), blood urea nitrogen, and creatinine were all significantly elevated POST and remained high in REC. There were inverse correlations between race time and N-linked substrate state PRE-POST, and changes in CK and LDH levels were significantly related to PLT mitochondrial LEAK and N-linked respiration PRE. Although race-related changes in respirometry parameters of PLT mitochondria were rather small, a somewhat more pronounced increase in the relative N-linked respiration in faster runners might suggest PLT CI as indicator of physical fitness. The higher PLT LEAK PRE and diminished increase of CK during the race may represent a prophylactic preconditioning and the slight but non-significant elevation of the antioxidant potential post-race as a protective consequence of the race-related oxidative stress and potential threat to the kidney. Our findings point toward an interrelationship between mitochondrial function of PLTs, individual fitness levels and extreme physical and metal stresses, which stimulates further research.

Human Platelet Mitochondrial Function Reflects Systemic Mitochondrial Alterations: A Protocol for Application in Field Studies

“…Moreover, detailed information on the separation process and the ambient conditions during the experiments were not reported [30]. Previously, we published an extensive HRFR protocol performed in the context of a field study [18]. Even though we could not determine distinct race-related changes in mitochondrial function, the association of PLT respiration with individual race performance, oxidative stress, muscle damage and renal dysfunction indicates the involvement of blood cells in governing systemic processes [18].…”

“…Previously, we published an extensive HRFR protocol performed in the context of a field study [18]. Even though we could not determine distinct race-related changes in mitochondrial function, the association of PLT respiration with individual race performance, oxidative stress, muscle damage and renal dysfunction indicates the involvement of blood cells in governing systemic processes [18]. If not, different methods can be used to assess blood-based bioenergetic changes, which are in part complementary, with each having their own strengths and limitations [15,42].…”

“…Two groups of participants were included in the evaluation: group 1 was sampled and assessed in field conditions, whereas for group 2, experiments were performed in the laboratory of Oroboros Instruments (LAB). Group 1 was composed of 10 participants of an ultramarathon project (age median: 51.5 years, range: 26-45 years; regular training/week: 8.5 h, range: 4-15 h), who were sampled three times (PRE-POST-REC) as described above [18]. Participants of group 2 were 9 recreational endurance athletes (running, cycling; age median: 31 years, range 29-41 years) who were sampled at least 24 h after their last training session.…”

“…Hence, metabolically highly active but homogenous PLTs might be a valuable surrogate to investigate systemic changes of mitochondrial function, since they are involved in a variety of systemic reactions (e.g., hemostasis, immunoregulation, inflammation or oxidative stress) [18][19][20]. Assessing PLT bioenergetics as a systemic marker has been performed in the context of various diseases [15,19,[21][22][23][24][25][26][27][28] as well as training studies [29][30][31][32][33].…”

Mitochondrial Respiration of Platelets: Comparison of Isolation Methods

“…Fundamental mitochondrial functions can be studied by assessment of the rate of oxygen consumption related to substrate oxidation and coupling control [ 2 , 3 ]. Supported by high-resolution respirometry (HRR) [ 4 ], the analysis of PLT respiration got into the forefront of research interest in biomedical fields [ 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. Mitochondrial dysfunction of PLT was observed in several human physiological and pathological conditions, including type II diabetes [ 12 , 13 ], aging [ 14 , 15 ], asthma [ 16 ], sepsis [ 8 , 17 , 18 , 19 , 20 ], schizophrenia, Huntington’s, Parkinson’s, and Alzheimer’s diseases [ 13 , 21 ].…”