Neutrophil death induced by a triathlon competition in elite athletes

Introduction/Purpose: The effect of a triathlon competition on death of neutrophils from elite athletes was investigated. Methods: Blood was collected from 11 sedentary volunteers and 12 triathletes under rest and after a Half Ironman triathlon competition (2-km swimming, 80-km cycling, and 20-km running). Results: The triathlon competition increased DNA fragmentation, phosphatidylserine externalization, and reactive oxygen species production in neutrophils when compared to the results at rest. The proportion of neutrophils with mitochondrial transmembrane depolarization was increased in the triathletes at rest and after competition as compared with sedentary volunteers. Plasma levels of thiobarbituric acid reactive substances were increased in triathletes after competition. Expression of bcl-xL (antiapoptotic) was decreased and that of bax (proapoptotic) was increased, whereas intracellular neutral lipid content was lowered in neutrophils after the triathlon. A positive correlation was found between the proportion of neutrophils with DNA fragmentation and the plasma free fatty acid levels (r = 0.688, P < 0.05), which was elevated by threefold after competition. Plasma levels of oleic, linoleic, and stearic acids were increased in triathletes after the competition when compared with sedentary volunteers. The plasma concentration of these three fatty acids, measured after the triathlon competition, was toxic for 3-h cultured neutrophils obtained from sedentary volunteers. The maximal tolerable (nontoxic) concentration of the fatty acids by 3-h cultured neutrophils was 100 mu mol.L-1 for oleic and linoleic acids and 200 mu mol.L-1 for stearic acid. Conclusion: The triathlon competition induced neutrophil death possibly by apoptosis as indicated by DNA fragmentation and phosphatidylserine externalization. The increase in plasma levels of oleic, linoleic, and stearic acids induced by the competition may be involved in the neutrophil death observed possibly by increasing the production of reactive oxygen species and by decreasing the accumulation of intracellular neutral lipid.

Induction of Lymphocyte Death by Short- and Long-Duration Triathlon Competitions

LEVADA-PIRES, A. C., M. F. CURY-BOAVENTURA, R. GORJAO, S. M. HIRABARA. E. F. PUGGINA, I. L. PELLEGRINOTTI, L. A. DOMINGUES FILHO, R. CURI, and T. C. PITHON-CURI. Induction of Lymphocyte Death by Short- and Long-Duration Triathlon Competitions. Med. Sci. Sporty Exerc., Vol. 4 1, No. 10, pp. 1896-1901, 2009. Purpose: The effect of triathlon competitions on death of lymphocytes from elite athletes was investigated. Material and Methods: Blood was collected from sedentary volunteers and triathletes at rest and after a short-duration triathlon (SDT) and after a long-duration triathlon (LDT-half Ironman) competitions. Results: The athletes had lowered lymphocyte proliferation capacity compared with sedentary volunteers either at rest or after the competitions. There was no difference in the parameters associated with lymphocyte death when sedentary volunteers were compared with triathletes at rest. Lymphocytes from triathletes after SDT competition showed an increase in DNA fragmentation, phosphatidylserine externalization, and mitochondrial transmembrane depolarization and did not alter membrane integrity when compared with cells from athletes at rest. In contrast, the LDT competition raised the proportion of lymphocytes with loss of membrane integrity when compared with cells from athletes at rest and did not change the apoptotic parameters. The LDT competition induced an increase of reactive oxygen species (ROS) production by lymphocytes compared with triathletes at rest. The SDT competition did not alter ROS production by lymphocytes when compared with cells from triathletes at rest. ROS production by lymphocytes after LDT competition was 60% higher than in SDT. Conclusions: Evidence is presented herein that an LDT competition caused lymphocyte death by necrosis, whereas an SDT induced lymphocyte apoptosis. The mechanism for lymphocyte death induced by the triathlon competitions may involve an increase in ROS production at different extents.

The effect of an adventure race on lymphocyte and neutrophil death

The effect of an adventure race (Ecomotion Pr), which lasted for 4-5 days, on neutrophil and lymphocyte death from elite athletes was investigated. Blood was collected from 11 athletes at rest and after the adventure race. The following parameters of cell death were measured in neutrophils and lymphocytes: cell membrane integrity, DNA fragmentation, mitochondrial transmembrane depolarization and reactive oxygen species (ROS) production. Phagocytosis capacity was also evaluated in neutrophils. The adventure race raised the proportion of cells with the loss of membrane integrity; lymphocytes by 14% and neutrophils by 16.4%. The proportion of lymphocytes with DNA fragmentation (2.9-fold) and mitochondrial transmembrane depolarization (1.5-fold) increased. However, these parameters did not change in neutrophils. ROS production remained unchanged in lymphocytes, whereas an increase by 2.2-fold was found in neutrophils due to the race. Despite these changes, the phagocytosis capacity did not change in neutrophils after the race. In conclusion, the Ecomotion Pr race-induced neutrophil death by necrosis (as indicated by the loss of membrane integrity) and led to lymphocyte death by apoptosis (as indicated by increase DNA fragmentation and depolarization of mitochondrial membrane).

Effect of short-term creatine supplementation on markers of skeletal muscle damage after strenuous contractile activity

The protective effect of short-term creatine supplementation (CrS) upon markers of strenuous contractile activity-induced damage in human and rat skeletal muscles was investigated. Eight Ironman triathletes were randomized into the placebo (Pl; n = 4) and creatine-supplemented (CrS; n = 4) groups. Five days prior to the Ironman competition, the CrS group received creatine monohydrate (20 g day(-1)) plus maltodextrin (50 g) divided in two equal doses. The Pl group received maltodextrin (50 g day(-1)) only. The effect of CrS (5 g day(-1)/kg body weight for 5 days) was also evaluated in a protocol of strenuous contractile activity induced by electrical stimulation in rats. Blood samples were collected before and 36 and 60 h after the competition and were used to determine plasma activities of creatine kinase (CK), lactate dehydrogenase (LDH), aldolase (ALD), glutamic oxaloacetic acid transaminase (GOT), glutamic pyruvic acid transaminase (GPT), and C-reactive protein (CRP) level. In rats, plasma activities of CK and LDH, muscle vascular permeability (MVP) using Evans blue dye, muscle force and fatigue were evaluated. Activities of CK, ALD, LDH, GOT, GTP, and levels of CRP were increased in the Pl group after the competition as compared to basal values. CrS decreased plasma activities of CK, LDH, and ALD, and prevented the rise of GOT and GPT plasma activities. In rats, CrS delayed the fatigue, preserved the force, and prevented the rise of LDH and CK plasma activities and MVP in the gastrocnemius muscle. CrS presented a protective effect on muscle injury induced by strenuous contractile activities.

Creatine supplementation reduces plasma levels of pro-inflammatory cytokines and PGE(2) after a half-ironman competition

Objective. The effect of creatine supplementation upon plasma levels of pro-inflammatory cytokines: Interleukin (IL) 1 beta and IL-6, Tumor Necrosis Factor alpha (TNF alpha), and Interferon alpha (INF alpha) and Prostaglandin E(2) (PGE(2)) after a half-ironman competition were investigated. Methods. Eleven triathletes, each with at least three years experience of participation in this sport were randomly divided between the control and experimental groups. During 5 days prior to competition, the control group (n = 6) was supplemented with carbohydrate (20g center dot d(-1)) whereas the experimental group (n = 5) received creatine (20 center dot d(-1)) in a double-blind trial. Blood samples were collected 48h before and 24 and 48h after competition and were used for the measurement of cytokines and PGE(2). Results. Forty-eight hours prior to competition there was no difference between groups in the plasma concentrations (pg center dot ml(-1), mean +/- SEM) of IL-6 (7.08 +/- 0.63), TNF alpha (76.50 +/- 5.60), INF alpha (18.32 +/- 1.20), IL-1 beta (23.42 +/- 5.52), and PGE(2) (39.71 +/- 3.8). Twenty-four and 48h after competition plasma levels of TNF alpha, INF alpha, IL-1 beta and PGE(2) were significantly increased (P < 0.05) in both groups. However, the increases in these were markedly reduced following creatine supplementation. An increase in plasma IL-6 was observed only after 24h and, in this case, there was no difference between the two groups. Conclusion. Creatine supplementation before a long distance triathlon competition may reduce the inflammatory response induced by this form of strenuous of exercise.