Exercise-induced oxidative stress leads hemolysis in sedentary but not trained humans

Abstract

Intravascular hemolysis is one of the most emphasized mechanisms for destruction of erythrocytes during and after physical activity. Exercise-induced oxidative stress has been proposed among the different factors for explaining exercise-induced hemolysis. The validity of oxidative stress following exhaustive cycling exercise on erythrocyte damage was investigated in sedentary and trained subjects before and after antioxidant vitamin treatment (A, C, and E) for 2 mo. Exercise induced a significant increase in thiobarbituric acid-reactive substance and protein carbonyl content levels in sedentary subjects and resulted in an increase of osmotic fragility and decrease in deformability of erythrocytes, accompanied by signs for intravascular hemolysis (increase in plasma hemoglobin concentration and decrease in haptoglobulin levels). Administration of antioxidant vitamins for 2 mo prevented exercise-induced oxidative stress (thiobarbituric acid-reactive substance, protein carbonyl content) and deleterious effects of exhaustive exercise on erythrocytes in sedentary subjects. Trained subjects' erythrocyte responses to exercise were different from those of sedentary subjects before antioxidant vitamin treatment. Osmotic fragility and deformability of erythrocytes, plasma hemoglobin concentration, and haptoglobulin levels were not changed after exercise, although the increased oxidative stress was observed in trained subjects. After antioxidant vitamin treatment, functional and structural parameters of erythrocytes were not altered in the trained group, but exercise-induced oxidative stress was prevented. Increased percentage of young erythrocyte populations was determined in trained subjects by density separation of erythrocytes. These findings suggest that the exercise-induced oxidative stress may contribute to exercise-induced hemolysis in sedentary humans.

Effect of exercise on erythrocyte osmotic fragility in high fat diet fed rats during intermittent fasting

“…However after such an adaptation period, exercise was found to exert no significant increase on erythrocyte osmotic fragility (20). A similar situation was also observed in humans which shows exercise is beneficial for trained individuals but exerting untoward effect on sedentary ones (21). Our findings can be interpreted as insufficient adaptation of rats to exercise although a preparatory exercise period was administered prior to exercise.…”

Constitutive immune function in European starlings,Sturnus vulgaris, is decreased immediately after an endurance flight in a wind tunnel

“…the breakdown of red blood cells (Lim et al, 2000). Exercise-induced haemolysis is well documented in humans (Sentürk et al, 2005), and has been suggested to occur in birds (Landys-Ciannelli et al, 2002;Piersma et al, 1996). If haptoglobin levels are depleted by binding to oxidative iron during migration, this may explain the decrease in haptoglobin we found with increasing flight duration.…”

Efeito do exercício de ultrarresistência sobre parâmetros de estresse oxidativo

“…Da mesma forma, Miyazaki et al (23) não observaram mudança nos marcadores de oxidação protéica, tanto após 12 semanas de treinamento quanto após exercício exaustivo, porém, avaliando sujeitos saudáveis, não atletas. Em outro modelo de exercício, Sentürk et al (24) , avaliando atletas em um teste incremental máximo, observaram dano às proteínas. Os atletas em nosso estudo não necessariamente chegaram à exaustão, tinham experiência de treinamento maior que 12 semanas e provavelmente mantiveram-se no metabolismo aeróbio a maior parte da competição, o que poderia explicar a diferença entre os resultados encontrados.…”

“…Sentürk et al (24) avaliaram os eritrócitos de indivíduos sedentários e atletas após um protocolo exaustivo em bicicleta, tanto antes quanto após um período de dois meses de suplementação com as vitaminas A, C e E. Os autores demonstraram que uma simples sessão de exercício intenso foi capaz de aumentar os parâmetros de estresse oxidativo e induzir deterioração da função e estrutura dos eritrócitos em sedentários, o que foi prevenido por dois meses de suplementação antioxidante. Contudo, esse comportamento não se repetiu nos indivíduos que eram treinados.…”