Background: Inflammatory enzymes and free radicals are important factors affecting the immune system. However, there seems to be no detailed information about the extent to which these factors can affect superoxide dismutase 1 gene expression in female athletes, especially in incremental exercises. Therefore, the aim of the present study was to investigate the correlation between superoxide dismutase 1 gene expression with lactate dehydrogenase (LDH) and free radicals in female athletes after an incremental intensity exercise.

Methods: Fifteen 22-24 year old female athletes from Urmia, Iran voluntarily participated in the study after completing an informed consent form in 2010. Venous blood samples were collected in three stages: prior to, immediately and 3 h after an incremental exercise (12 km/h at a 5% gradient for 20 min). Real-time PCR was used to assess superoxide dismutase1 (SOD-1) gene expression as was an autoanalyzer for hydrogen peroxide (H2O2) and LDH concentrations.

Results: LDH concentration significantly increased in both stages of the exercise (immediately and 3 h after the exercise), (respectively, P=0.009 and P=0.026), but H2O2 concentration significantly increased only in the recovery phase (P=0.002). SOD-1 mRNA did not significantly increase in any stage of the exercise (P=0.05). Moreover, there was only a significant correlation between SOD-1 mRNA and H2O2 increase (P=0.014).

Conclusion: Incremental exercise increased H2O2 and LDH levels in female athletes but only free radicals had a significant effect on SOD-1 gene expression.