Search

Our aim was to investigate the effects of an exercise test on some indices of oxidative status and endothelial function, in trained and untrained subjects. We examined lipid peroxidation, nitric oxide metabolites (NOx) and their ratio before and after a cardiopulmonary test, using a cycloergometer. We enrolled 60 male subjects who practiced sport unprofessionally, subdivided in two groups (A and B) according to the values of VO2max. Group A included sportsmen with poor or fair aerobic fitness (VO2max <39 ml/Kg/min), group B sportsmen with average to excellent aerobic fitness (VO2max >39 ml/Kg/min). The control group included 19 male sedentary subjects. Lipid peroxidation was evaluated by detection of the thiobarbituric acid-reactive substances (TBARS); the NOx were evaluated employing the Griess reagent. At rest, in comparison with sedentary controls, an increase in TBARS, NOx and TBARS/NOx ratio was found in all sportsmen and partially in the two groups. After the cardiopulmonary test, the increase of TBARS and TBARS/NOx ratio was significantly more evident in sedentary controls than in sportsmen. No variation was observed for NOx in any group. These data suggest that sportsmen are protected against the acute oxidative stress induced by an exercise test, and that protection is not strictly dependent on the aerobic fitness. [ABSTRACT FROM AUTHOR]

Aim Alpha-thalassaemia is known to reduce intra-erythrocyte Hb S (sickle haemoglobin) concentration in sickle cell trait ( SCT) subjects. Because Hb S was shown to increase oxidative stress, the purpose of this study was to assess the effects of the coexistence of α-thalassaemia and SCT on oxidative stress markers and nitric oxide ( NO) metabolism after an acute physical exercise. Methods Forty subjects (age: 23.5 ± 2.21 years), SCT carriers ( Hb AS) or healthy subjects ( Hb AA), with (-α T) or without (- Nα T) an associated α-thalassaemia took part in the study. Plasma markers of oxidative stress [advanced oxidation protein products ( AOPP), protein carbonyl, malondialdehyde ( MDA) and nitrotyrosine], anti-oxidant defences and NO metabolism ( NOx) were measured at rest ( Trest), immediately following an incremental maximal exercise test ( Tex) and during recovery ( T1h, T2h and T24h). Results Malondialdehyde expressed as the percentage of changes from baseline was significantly higher in the Hb AS- Nα T compared with Hb AS-α T during recovery (+36.3 ± 14.1% vs. −1.8 ± 13.2% at T1h, P = 0.02; +36.6 ± 13.4% vs. −11.4 ± 12.5% at T2h, P = 0.004 and +24.1 ± 12.3% vs. −14.4 ± 11.5% at T24h, P = 0.02 in Hb AS- Nα T vs. Hb AS-α T). Compared with Hb AS- Nα T, Hb AS-α T had a higher NOx change from baseline at Tex (−23.4 ± 20.6% vs. +57.7 ± 19.3%, respectively; P = 0.005) and lower nitrotyrosine change from baseline at T1h (+7.2 ± 22.2% vs. +93.5%±29.3%, respectively; P = 0.04). Conclusion All these data suggest that the presence of α-thalassaemia may blunt the higher level of oxidative stress and the impaired bioavailability of NO observed in the SCT carriers. [ABSTRACT FROM AUTHOR]