本研究主要目的在於探討衰竭運動與肌纖維類型對超氧化物岐化�t的影響。 實驗 中以 50 隻雄性的白老鼠為受試對象，隨機分配至衰竭運動組與控制組。衰竭運動組的老鼠在老鼠跑步機上以每小時 2 公里、陡度 15 ％的快速、高陡度運動強度跑至衰竭為止。 衰竭運動後取出老鼠右後腿的比目魚肌、蹠肌、腓腸肌紅肌部與腓腸肌白肌部。控制組的老鼠亦在同一時間取出上述肌纖維。 超氧化物岐化�t的含量是採用 McCord ＆ Fridovich 的方法來測量。所得的數據是以二因子重複量數變異數分析來考驗衰竭運動與肌纖維類型對超氧 化物岐化�t的影響。結果顯示，衰竭運動促使老鼠骨骼肌的超氧化物岐化�t顯著上升。本研究採取的四種肌纖維的超氧化物岐化�t對於衰竭運動的反應並不一致。但是老鼠紅肌（比目魚肌、腓腸肌紅肌部）中的超氧化物岐化�t在衰竭運動的情況下，顯著高於控制組的超氧化物岐化�t；至於白肌（蹠肌、腓腸肌白肌部）的超氧化物岐化�t對於衰竭運動的反應，與控制組就沒有顯著的差異存在。因此，本研究認為衰竭運動產生了氧化壓力，使老鼠骨骼肌增 加超氧化物岐化�t的含量以為因應；然而因內肌肉類型不同，生化特性有別，徵召型態亦有差異，故而使紅肌的超氧化物岐化�t含量比白肌更能顯著提升

　　　　　The purpose of this study was to investigate the effects of exhaustive exercise and muscle fiber type on superoxide dismutase (SOD). Fify male rats were randomly divided into the following two groups: (1)exhaustive exercise, and (2)control group (n=25). The strenuous exercise was performed on a rodent treadmill at a speed of 2 Km/h up a 15% grade until exhaustive. The soleus, plantaris, and red and white gastrocnemius muscles of the rat right hindlimb were removed following exhaustive exercise. Control ratswere sacrificed at the same time as the exhaustive exercise group. The SOD activity was determined using the method of McCord & Fridovich. Two way repeated measure ANOVA was performed to examine the effects of exhaustive exercise and muscle fiber type on SOD. The finding showed that exhaustive exercise resulted in a singificant increase in SOD. The finding showed that exhaustive exercise resulted in a singificant increase in SOD activity of rat skeletal muscle. There was no identical alteration among 4 kinds of fiber types on SOD activities in response to exhaustive exercise. Moreover, the activity of SOD induced by exhaustive exercise on red fiber (soleus and red gastrocnemius) was significantly higher than control group, while SOD activity on white fiber (plantaris and white gastrocnemius) was not significant different between exhaustive exercise and control group. It was concluded that exhaustive exercise could result in oxygen free radical stress. The higher SOD activity in red fiber during exercise may be due to fiber type difference, biochemical property, and fiber pattern recruited.