Induction of lymphocyte death by short- and long-duration triathlon competitions.
OBJECTIVE
The effect of triathlon competitions on death of lymphocytes from elite athletes was investigated.


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.
Levada-Pires
Adriana Cristina
AC
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Brazil.
Cury-Boaventura
Maria Fernanda
MF
Gorjão
Renata
R
Hirabara
Sandro Massao
SM
Puggina
Enrico Fuini
EF
Pellegrinotti
Idico Luiz
IL
Domingues Filho
Luiz Antonio
LA
Curi
Rui
R
Pithon-Curi
Tania Cristina
TC
D000328:Adult; D017209:Apoptosis / Q000502:physiology; D001642:Bicycling / Q000502:physiology*; D002462:Cell Membrane / Q000473:pathology; D049109:Cell Proliferation; D053938:DNA Fragmentation; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism / Q000473:pathology* / Q000502:physiology*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D009336:Necrosis / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012420:Running / Q000502:physiology*; D013550:Swimming / Q000502:physiology*; D013997:Time Factors
D017382:Reactive Oxygen Species