| 摘要: | Purpose: Exercise preconditioning has been known to reduce strenuous exercise-induced oxidative damages. To understand the underlining mechanisms, plasma samples isolated from exhausted exercises were used to investigate the possible protection effect on RBC with or without following hypoxia/reoxygenation. Methods: Eight healthy male participants were recruited voluntarily (age: 28.9 ± 8.3 yr, height: 170.1 ± 5.9 cm, weight: 68.9 ± 7.4 kg). Blood samples were collected before (resting, r) and after (post exercise, e) running by Bruce graded exercise testing (GXT). Plasma and RBC were separated and then recombined again into 4 groups: rWB (rWhole Blood), rRrP (rRBC + rPlasma), rReP (rRBC + ePlasma), rRs (rRBC + PBS). All groups were then treated with hypobaric hypoxia at PO2 = 45 mmHg (H/N) or normbaric normoxia at PO2 = 152 mmHg (N/N) for 1 hr and then recovered by N/N for 5 min. Data were to compare differences among the groups at indicators including antioxidant enzyme activities, peroxidized lipid (TBARS), lactate, glucose and uric acid. Results: As compared to the control group, plasma with exercise preconditioning had significantly increased levels of lactate (15.26 ± 0.73 mM vs. 2.88 ± 0.19 mM, p ＜ .05), glucose (120.18 ± 6.40 mg．dL^(-1) vs. 98.12 ± 5.09 mg．dL^(-1), p ＜. 05) and uric acid (5.64 ± 0.53 mg．dL^(-1) vs. 4.56 ± 0.48 mg．dL^(-1), p ＜ .05). Except for eReP, RBC's TBARS level was significantly elevated in rWB, rRrP, rRs after N/N treatment as compared to rP (146.35 ± 32.48 mnol．gHb^(-1), 141.97 ± 34.4 mnol．gHb^(-1), 148.42 ± 29.8 mnol．gHb^(-1) vs. 59.72 ± 16.31 mnol．gHb^(-1), ＜ .05) or eP along (146.35 ± 32.48 mnol．gHb^(-1), 141.97 ± 34.4 mnol．gHb^(-1), 148.42 ± 29.8 mnol．gHb^(-1), vs. 50.53 ± 21.33 mnol．gHb^(-1), p＜ .05). However, this protection effect contributed to eP cannot be observed in groups after H/ treatment. All antioxidant enzyme activities among the groups were not different in both N/N and H/N treatments. Conclusion: Plasma with exhausted exercise preconditioning may reduce RBC peroxidized lipid damages but may not in hypoxia and reoxygenation. Further studies are needed to explore the role of uric acid in this reaction. |
