This study sought to examine the effects of partial vascular occlusion (PVO) on oxidative stress markers in response to resistance exercise and at rest in young resistance-trained males. 12 resistance-trained males performed 6 conditions in random counterbalanced order: rest (R), low-intensity (LIRE: 30% 1RM) and moderate-intensity (MIRE: 70% 1RM) resistance exercise with or without PVO. Blood samples were obtained before and immediately after each condition and plasma protein carbonyls (PC), glutathione ratio, oxygen radical absorbance capacity (ORAC), and xanthine oxidase (XO) were evaluated. The addition of PVO resulted in significantly greater plasma PC and glutathione ratio in the rest condition. During LIRE the addition of PVO significantly attenuated plasma PC. The MIRE condition, independent of PVO, resulted in significantly higher PC concentration and glutathione ratio compared to the rest and LIRE conditions. The addition of PVO during MIRE resulted in a significant increase in PC. Thus, this study revealed that PVO increased oxidative stress at rest and enhanced the oxidative stress response to MIRE, but when combined with LIRE oxidative stress was attenuated. These findings suggest that the utilization of PVO during LIRE may alter ROS-induced accumulation in the blood which may influence cellular signaling.

Few studies compare sampling protocol effect on sweat composition. Here we evaluate the impact of sweat stimulation mode and site of collection on lipid mediator composition. Sweat from healthy males (n=7) was collected weekly for three weeks from the volar forearm following either pilocarpine iontophoresis or exercise, and from the forearm, back and thigh following pilocarpine iontophoresis only. Sweat content of over 150 lipid mediators were measured by liquid chromatography-tandem mass spectrometry. Seventy lipid mediators were routinely detected, including prostanoids, alcohols, diols, epoxides, ketones, nitrolipids, N-acylethanolamides, monoacylglycerols, and ceramides. Detected lipid mediators appeared unaffected by sampling site, though the forearm was the most consistent source of sweat. Pilocarpine-induced sweat showed increased concentrations of most detected compounds. Moreover, lipid mediator concentrations and profiles were temporally stable over the study duration. Sweat therefore appears to be a consistent and anatomically-stable source of lipid mediators, but care must be taken in comparing results obtained from different stimulation techniques.

The present study aimed to determine the day to day variability and reliability of several blood oxidative stress markers at rest in a healthy young cohort over a four-week period. Twelve apparently healthy resistance trained males (24.6 ± 3.0 yrs) were tested over 7 visits within 4 weeks with at least 72 hrs between visits at the same time of day. Subjects rested 30 minutes prior to blood being obtained by vacutainer. Results. The highest IntraClass correlations (ICC's) were obtained for protein carbonyls (PC) and oxygen radical absorbance capacity (ORAC) (PC = 0.785 and ORAC = 0.780). Cronbach's α reliability score for PC was 0.967 and for ORAC was 0.961. The ICC's for GSH, GSSG, and the GSSG/TGH ratio ICC were 0.600, 0.573, and 0.570, respectively, with Cronbach's α being 0.913, 0.904, and 0.903, respectively. Xanthine oxidase ICC was 0.163 and Cronbach's α was 0.538. Conclusions. PC and ORAC demonstrated good to excellent reliability while glutathione factors had poor to excellent reliability. Xanthine oxidase showed poor reliability and high variability. These results suggest that the PC and ORAC markers were the most stable and reliable oxidative stress markers in blood and that daily changes across visits should be considered when interpreting resting blood oxidative stress markers.