Role of adenosine deaminase in alteration of cortisol and tumor necrosis factor α concentration following exhaustive exercise sessions

Abstract

Context: Cortisol and tumor necrosis factor-α (TNF-α) has a significant role on the immune system. Previous studies have shown a significant increase in cortisol and TNF-α in athlete; however, the alteration of adenosine deaminase (ADA) activity in athletes has not been previously reported. Aims: This study was aimed to investigate the effect of exhaustive exercise on cortisol, TNF-α and serum ADA activity in endurance runners. Settings and Design: All endurance male athletes were enrolled in this case control study. Subjects and Methods: The participants were submitted to the same experimental protocol used in the exercise trials, they run on a treadmill until exhausting state. Saliva and blood sample were collected in resting and immediately after exercise; serums were separated and stored at −70°C pending assays. Serum was analyzed for ADA activity and TNF-α. Salivary cortisol measured by enzyme-linked immunosorbent assay method. Statistical Analysis Used: Data was analyzed using the statistical package for the social sciences 16 (SPSS Inc., Chicago) and one-sample Kolmogorov-Smirnov test. Results were presented as mean ± standard deviation and independent samples t-test used to compare mean differences. In addition, linear regression analysis was performed and means of the Pearson's correlation coefficient (r) were determined to show the correlation between variables. Results: Cortisol and TNF-α elevated following intensified training compared with the resting state. There was a significant increase in serum ADA activity between athletes and non-athletes groups. In addition, our results showed a strong direct correlation between serum total ADA activity and TNF-α. Conclusions: Based on the obtained data, an acute period of intensified training can induce an increase of ADA activity accompanies with the increase of cortisol and TNF-α. ADA is involved in the immune system development. Our results hypothesized that ADA can be associated with an increase in fatigue which lends to reduced physical activity. We showed that excessive exercise can induce an inflammatory response resulting in elevated levels of cortisol and TNF-α and perhaps by increasing activity of adenosin deaminase.