運動後多形核細胞內氧化壓力與去氧核醣核酸的變化情形

Alteration of oxidative stress and DNA damage in PMN leukocytes after consecutive intense training

激烈運動因為有氧代謝過程的增加，被認為會產生氧化壓力，並導致氧化傷害，尤其是細胞內的去氧核醣核酸（DNA）；而此氧化傷害可能是造成免疫低下的原因之一。目的：要探討連續性高強度運動訓練後，多形核細胞（PMN）所產生的氧化壓力與去氧核醣核酸之變化情形。方法：以12位耐力性選手為受試者，並用85%最大攝氧量的速度在跑步機上，連續3天，每次跑30分鐘。分別在第一天跑前（D1）、跑後即刻（D1’），第三天跑前（D3）、跑後即刻（D3’），第五天（D5）及第七天（D7），收集受試者約10毫升手臂靜脈血。多形核細胞中的超氧自由基、過氧化氫、榖胱甘肽等濃度及DNA的氧化傷害值皆利用流式細胞儀（FACS caliber flow cytometer）偵測與分析。結果：細胞內超氧自由基與過氧化氫在各個時間點均無顯著變化，但過氧化氫濃度在運動後有增加的趨勢。榖胱甘肽濃度在D1’與D5有明顯增加（p<.05），但在D7則是減少（p<.05）。DNA的氧化傷害在D3和D3’皆有顯著的增加（p<.05）。結論：連續三天高強度運動訓練可能會誘發多形核細胞內的氧化傷害，並且有累積性增加的現象。

Polymorphonuclear leukocyte (PMN) plays a critical role in the immune defense system against infections. Oxidative damage in PMN is probably one of the mechanisms behind immune dysfunctions. Oxidative stress has been associated with strenuous exercise due to increasing aerobic metabolism and could be responsible for oxidative damage, especially intracellular DNA. Purpose: The purpose of this study was to investigate the effects of consecutive high intense exercise-induced oxidative stress on accumulation of oxidative DNA damage in PMN leukocytes. Methods: Twelve endurance subjects who performed aerobic exercise for 3 consecutive days (85 % V.O2 max) and every event for 30 min were recruited to this study. Venous blood samples were collected from subjects running before (D1), immediately after Day1 (D1') and Day3 before (D3), Day3 running immediately after (D3'), Day5 (D5), and Day7 resting (D7) and respectively. Superoxide, hydroxyl peroxide (H2O2), reduced glutathione (GSH) concentrations and levels of oxidative DNA damage in PMN were measured by FACS caliber flow cytometer. Results: Superoxide is no difference in time course. To compare D1 with D3 and D1' with D3' individually; there was no different in H2O2 concentration. Intracellular GSH concentration was significantly increasing in D1' and D5, but decreasing in D7. The level of oxidative DNA damage was notably high in D3 and D3' (p< .05). Conclusion: For 3 consecutive days (85% V.O2 max) high intense exercise could probably lead to accumulation of oxidative damage in PMN leukocytes.