We studied the effects of 30 minutes of exercise on T lymphocyte counts and proliferative responses of peripheral blood mononuclear cells (PBMC) in 25 runners. Exercise resulted in a T lymphocytosis in the immediate post-exercise period in all subjects (p < 0.001), and reduced CD4+/CD8+ ratios in 22/25 subjects (p = 0.001). The change was due primarily to a 2.2-fold increase in CD8+ cells (p < 0.001). Exercise also reduced PBMC mitogenic responses to phytohemagglutinin (PHA) in 13/14 subjects (p = 0.049), and to pokeweed mitogen (PWM) in 11/14 subjects (p = 0.022), but not to concanavalin A. Postrun sera from 5 of 6 subjects inhibited PHA but not PWM responses of resting autologous PBMC with normal CD4+/CD8+ ratios (p < or = 0.05): indomethacin and monocyte depletion blocked the serum inhibition (p = 0.003, p = 0.0006, respectively). We conclude that post-exercise suppression of mitogenic responses to PHA is due to the release of a serum factor(s) capable of inducing prostaglandin synthesis by circulating monocytes, whereas exercise-induced suppression of PWM responses depends primarily on the reversal of CD4+/CD8+ ratios.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-2-1353 |
| Date | 01 June 1993 |
| Creators | Smith, J, Chi, D, Salazar, S, Krish, G., Berk, S., Reynolds, S., Cambron, G. |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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