AIM: The duration-dependence of the effect of forced treadmill exercise on the immune system is a subject of ongoing research. In this study, the effect of forced treadmill exercise on immune responses was investigated by evaluating the lymphocyte subset fractions in the peripheral blood and spleen of Sprague-Dawley rats. EXPERIMENTAL DESIGN: Comparative investigation over 8 weeks. SETTING: Experimental animal laboratory. PARTICIPANTS: Male Sprague-Dawley rats 5 weeks of age, weighing 150+/-10 g. INTERVENTIONS: Animals were randomly assigned to one of the 4 following groups: the control group, the 1-week-exercise group, the 4-week-exercise group, and the 8-week-exercise group. MEASURES: Lymphocyte subset fractions, including those for T, B, CD4+, and CD8+ cells and the T/B and CD4+/CD8+ ratios in the peripheral blood and spleen were measured via flow cytometric analysis after treadmill exercise. RESULTS: The T cell and CD4+ cell fractions in both the peripheral blood and spleen were increased significantly after 8 weeks of treadmill exercise, but the B cell and CD8+ cell fractions did not change significantly. CONCLUSION: From the results of the present study, it is suggested that a period of one week is insufficient to eliminate the effects of exercise-induced stress, that 4 weeks are needed to return to the control state, and that at least 8 weeks are needed in order for exercise of moderate intensity to have a positive effect on the immune system.
AIM: The duration-dependence of the effect of forced treadmill exercise on the immune system is a subject of ongoing research. In this study, the effect of forced treadmill exercise on immune responses was investigated by evaluating the lymphocyte subset fractions in the peripheral blood and spleen of Sprague-Dawley rats. EXPERIMENTAL DESIGN: Comparative investigation over 8 weeks. SETTING: Experimental animal laboratory. PARTICIPANTS: Male Sprague-Dawley rats 5 weeks of age, weighing 150+/-10 g. INTERVENTIONS: Animals were randomly assigned to one of the 4 following groups: the control group, the 1-week-exercise group, the 4-week-exercise group, and the 8-week-exercise group. MEASURES: Lymphocyte subset fractions, including those for T, B, CD4+, and CD8+ cells and the T/B and CD4+/CD8+ ratios in the peripheral blood and spleen were measured via flow cytometric analysis after treadmill exercise. RESULTS: The T cell and CD4+ cell fractions in both the peripheral blood and spleen were increased significantly after 8 weeks of treadmill exercise, but the B cell and CD8+ cell fractions did not change significantly. CONCLUSION: From the results of the present study, it is suggested that a period of one week is insufficient to eliminate the effects of exercise-induced stress, that 4 weeks are needed to return to the control state, and that at least 8 weeks are needed in order for exercise of moderate intensity to have a positive effect on the immune system.
Authors: Valdenilson Ribeiro Ribas; Hugo André de Lima Martins; Marcelo Tavares Viana; Simone do Nascimento Fraga; Severino Marcos de Oliveira Carneiro; Bruno Henrique Andrade Galvão; Alice Andrade Bezerra; Célia Maria Machado Barbosa de Castro; Everton Botelho Sougey; Raul Manhães de Castro Journal: Rev Bras Hematol Hemoter Date: 2011