Oxidative stress effects on endothelial cells treated with different athletes' sera.

Purpose: Exercise training is a nonpharmacological intervention that improves cardiovascular function and enhances endothelial homeostasis in patients with cardiovascular diseases. However, the amount of benefit achieved varies widely depending on the type and duration of exercise. Moreover, data about the long-term effects of physical activity are scarce.
Methods: In this study, endothelial cells, exposed or not to oxidative stress, were conditioned with sera from athletes regularly participating in sports classified as "aerobic" (triathlon), "mixed aerobic-anaerobic" (soccer), and "anaerobic" (sprint running).
Results: Functional and hemodynamic variables did not differ between groups of athletes, whereas there were dramatic changes in serum markers for oxidative stress. Lipid peroxidation assessed by the thiobarbituric acid reactive substances assay and catalase activity were the lowest and nitric oxide availability was the highest in sera of triathletes. Endothelial cells cultured in serum from triathletes (T-endothelial cells) had the highest survival, evaluated by viability assay, BrdU incorporation, and senescence-associated β galactosidase assays, and preserved the endothelial appearance before and after stress in contrast to the cells grown in sera from the other athletes. T-endothelial cells also had the highest catalase messenger RNA expression and, after stress, the highest catalase activity of all the endothelial cells. Moreover, poststress activity of Sirt1, a NAD(+)-dependent deacetylase involved in cellular stress resistance and a key regulator of longevity, was significantly increased in T-endothelial cells.
Conclusions: Different types of exercise training induced different molecular effects in terms of survival, morphology, and antioxidant system efficiency. The in vitro technique used herein may help to shed light on the molecular basis of effects of long-term physical activity in humans.