Abstract des Autors

In the present study we assessed the effect of physical training on Laser Doppler skin flux (LDF) and nitric oxide (NO) release, before and after 3 min of brachial artery occlusion. To this end we performed laser Doppler measurements and the venous plasma assay of nitrite/nitrate (NOx) on 10 sedentary healthy subjects and 10 endurance athletes. The sedentary control subjects had lower basal and post reperfusion levels of NOx as compared to athletes (mean ± SE: 27.8 ± 3.5 vs. 33.2 ± 3.4, 48.6 ± 7.9 vs. 60.1 ± 10.1 µmol/L; p<0.05). LDF at baseline was not significantly different in the two groups (157.5 ± 7.9 and 176.64 ± 26.7 PU for sedentary subjects and athletes, respectively) while post ischemic LDF was significantly lower in nonathletic subjects than in athletes (209.9 ± 13 and 343.8 ± 21.3 PU, p<0.001). In both groups the hyperaemic stimulus significantly increased LDF and NOx levels (p<0.01 and p<0.05, respectively). The flow reserve, estimated as peak/basal LDF, was significantly lower in control subjects than in athletes (1.34 ± 0.2 and 2.32 ± 0.9, respectively, p<0.01). In athletes, as opposed to sedentary subjects, a direct correlation was found between plasma NOx concentration and LDF both in basal conditions (r=0.92; p<0.001), and during hyperaemia (r=0.84; p<0.01). In conclusion, compared to sedentary subjects, athletes had an enhanced nitric oxide release. Hyperaemia increased LDF and nitric oxide levels both in sedentary subjects and in athletes. Verf.-Referat