B-30 Free Communication/Poster - Immunology I: JUNE 2, 2010 1:00 PM - 6:00 PM: ROOM: Hall C
A substantial body of evidence suggests strenuous exercise causes perturbations to the immune system and increase reactive oxygen species formation.Perturbations to these systems occur during exercise, yet information regarding the interactions between them are sparse.
PURPOSE: The purposes of this study were to: 1) examine the immune and oxidative stress responses following high intensity interval training (HIIT); 2) determine whether changes in antioxidant enzyme gene expression and enzyme activity occurs in lymphocytes following HIIT; and 3) determine whether changes in antioxidant expression and activity would improve lymphocyte cell viability following hydrogen peroxide exposure in vitro.
METHODS:. Eight recreationally active males completed three identical high-intensity protocols separated by 48hrs. Blood samples were obtained each day at pre, post, 3hrs, and 24hrs post-exercise. Circulating leukocytes, lymphocytes, and neutrophils; lymphocyte antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, catalase), lymphocyte gene expression, lymphocyte cell viability, and plasma malondialdehye (MDA) levels were measured. Statistical analysis was peformed using ANOVA with repeated measures (p < 0.05).
RESULTS: Results showed an increase in circulating lymphocytes and antioxidant enzyme activity immediately following HIIT. MDA levels significantly increased post-exercise on Day1 and 2. No significant changes in antioxidant gene expression were found. Cell viability improved following Day 1 of HIIT and significantly decreased during the 3hr post-exercise period compared to pre and 24hr.
CONCLUSIONS: Lymphocytes respond to oxidative stress by increasing antioxidant enzyme activity. Adaptations appear to occur at the post-transcriptional level as no changes in gene expression were found. HIIT causes oxidative stress but did not induce a significant post-exercise lymphopenia. In vitro analyses suggest lymphocytes may be fortified by increasing their antioxidant enzyme activities and become more resistance to subsequent episodes of oxidative stress. Furthermore, the in vitro analysis confirms that lymphocytes are more vulnerable to cytotoxic molecules during recovery from strenuous exercise.