Lymphocyte and cytokines after short periods of exercise.

The purpose of this study was to verify the effects of short periods of exercise of different intensity on lymphocyte function and cytokines. Thirty Wistar rats, 2 months old, were used. They were divided into five groups of six rats: a sedentary control group; a group exercised for 5 minutes at low intensity (5 L); a group exercised for 15 minutes at low intensity (15 L); and groups exercised at moderate intensity (additional load of 5 % of body weight) for 5 minutes (5 M) or for 15 minutes (15 M). The parameters measured were: total leukocytes, neutrophils, lymphocytes, monocytes, lymphocytes from lymph nodes, serum cytokines (IL-2, IL-6 and TNF-alpha), lymphocyte mitochondrial transmembrane potential, viability and DNA fragmentation. ANOVA two way followed by Tukey's post hoc test (p <or= 0.05) was used. The exercised groups exhibited a significant increase in total leukocytes, tissue and circulating lymphocytes in comparison with the control group. There was a significant decrease in lymphocyte viability and decrease in DNA fragmentation for the 15 M group when compared with the control. There was a decrease in the level TNF-alpha in the 5 M and 15 M groups. Short-term, low- and moderate-intensity exercise may be considered for sedentary individuals beginning to exercise, since no deleterious alterations were observed in lymphocyte function.