Immunomodulatory Effect of Warm Water Swim-stress in Adult Female Sprague Dawley Rats

This study investigates the immunomodulatory effect of warm water swim-stress. Twenty Sprague Dawley rats, divided into 4 groups were used. Control Group (CG) rats were not exposed to any kind of stress. Experimental Group 1 (EG1) rats were exposed to mild/short-term stress for 3 min, experimental Group 2 (EG2) rats were exposed to moderate stress for 6 min, while experimental group 3 (EG3) rats were exposed to severe/long-term stress for 10 min. All experimental rats were exposed to warm water swim-stress once daily for 20 consecutive days. CD4 cell count, Total White Blood Cell (TWBC) Count and Differential White Blood Cell (DWBC) count were determined. The results of this experiment showed that there was a significant increase in the CD4 cell counts and TWBC counts of EG1 and EG2 when compared with CG. However, there was a significant decrease in the CD4 cell and TWBC counts of EG2 when compared with EG1. There was a significant decrease in the CD4 cell and TWBC counts of EG3 when compared with CG, EG1 and EG2. There was a significant decrease in neutrophil counts of EG1 and EG2 when compared with CG. There was also a significant increase in lymphocyte counts of EG1 and EG2 when compared with CG. However, there were no significant alterations in the neutrophil and lymphocyte counts of EG3 when compared with CG. The present study showed that mild/short term and moderate warm water swim stress stimulate the immune response, while severe/chronic stress suppresses the immune system.