Background: Stress is an integral part of modern life results in long-term alterations of the immune system. Exercise may have effects on immune functioning.
Aim of the Work: To study chronic stress-induced alterations on serum corticosterone levels, splenic antioxidants, splenic morphology, and splenic T cell population, also to investigate the influence of swimming-exercise to counteract these alterations.
Methods: Forty-rats were equally divided into four groups: control group, exercised group (EX-group), immobilization stressed group (IS-group) and exercised & immobilization stressed group (EX&IS-group). Assessment of serum corticosterone, splenic malondialdehyde (MDA), splenic total antioxidant capacity (TAC), as well as histological and immunohistochemical approaches were done.
Results: EX-group had similar results if compared to control group apart from significantly increased TAC and decreased MDA levels. IS-group had significantly increased corticosterone and MDA with significantly decreased TAC levels, significantly decreased white pulp number and size, loss of the prominent marginal zone and expansion of red pulp with decreased cellularity if compared to control and EX-groups. While, exercise in EX&IS-group significantly decreased corticosterone and splenic MDA with significantly increased TAC levels, preserved the normal architecture with significant increased number and size of the lymphatic follicles and increased cellularity compared to the IS-group. Immunohistochemicaly, IS-group had significantly decreased CD3+ and CD4+ cells with a significantly increased CD8+ and apoptotic cells. Meanwhile, exercise prevent the effects of stress in EX&IS-group which had significantly increased CD3+ and CD4+ cells and significantly decreased CD8+ and apoptotic cells compared to the IS-group.
Conclusion: Swimming exercise showed significant counteraction against the effect of chronic stress on serum corticosterone levels, splenic antioxidants, spleen microarchitecture changes and its cellular phenotypes, and also suppression of apoptosis of splenocytes. Exercise conditioned the animals to tolerate the various effects of stress, in turn, it could be hypothesized that active lifestyle is likely to be beneficial to immune function in stress exposure.