目的:探討離心運動對骨骷肌粒腺體釋出細胞色素c(cytochrome c， cyt-c) 及細胞凋亡誘發因子(apop的sisinducing factor， AIF)的影響。方法:以8週 齡雄鼠(Sprague-Dawley)為本研究之受試對象，將實驗動物隨機分成控制組(con甘01; N=4)、運動控制組(level running， LR; N= 16)及離心運動組 (downhill running， DHR; N=16) 0 LR (坡度O度)及DHR(坡度必度)之實騷動物於動物跑步機上以20mlmin之速度跑步90分鐘，每回合跑5分鐘休 息2分，共計18回合。LR典DHR分別於運動後第o(n=4)， 24 (n=4)， 48 (n=4) 及72(n=4)小時將實驗動物犧牲，取出前肢脈三頭肌(triceps brachii muscle) 進行後續分析。結果:DHR在運動後第O小時之活化的c-Jun氯基末端激臨 (phosphO!γlated c-Jun NH2-terminal kinase)表現量高於LR(p < .05)。運動後第 24及48小時之DHR粒腺體釋出cyt-c至細胞質的表現量高於LR (p< .05)。 LR及DHR對粒腺體釋出AIF至細胞質的表現量均無顯著差異(p> .05) ，但DHR在運動後第24小時細胞核核內AIF表現量高於LR(p < .05)。結論: (一)在運動後第24及48小時，單次之離心運動會增加骨骷肌粒腺體釋出細胞色素c至細胞質的表現量。(二)單次之離心運動不會影響骨骷肌粒腺體釋出AIF至細胞質的表現量，但在運動後第24小時具有增加細胞核核內AIF表現 量的現象。

Purpose: This study was to investigate the effect of eccentric exercise on mitochondria to release the cytochrome c (cyt -c) and apoptosis inducing factor (AIF) in skeletal muscle. Methods: Animals， male Sprague-Dawley rats， were randomly assigned to either a rest control group (N=4)，an exercise control group (levelrunning， LR; N=16) or an eccentric exercise group (downhill running， DHR; N=16). The rats in both LR and DHR ran on animal treadmill at a constant speed of20 mlmin on the level (0 degree incline) or downhill (a 16 degree decline) for 90 min. The 90 min running time was divided into 5 min runs separated by 2 min rest intervals (18 bouts). Rats were sacrificed at post-exercise 0 hour (PEO; n=4)， post-exercise 24 hours (PE24; n=4)， post-exercise 48 hours (PE48; n=4) and post-exercise 72 hours (PE72; n=4)， respectively. The triceps brachii (TB) muscle was dissected out and frozen in liquid nitrogen rapidly. Results: The phosphorylated c-Jun NH2-terminal kinase (p-JNK) expression of DHR was significantly higher than LR at PEO (p < .05). The expression level of cytosolic cyt-c released from mitochondria of DHR which was significantly higher than LR at both PE24 and PE48 (p < .05). The expression level of nuclei AIF of DHR was significantly higher than LR at PE24 (p< .05). Conclusions: 1) A single bout eccentric exercise might increase the expression level of cytosolic cyt-c released from mitochondria in TB at both PE24 and PE48. 2) A single bout eccentric exercise didn't affect the expression level of cytosolic AIF released from mitochondria in TB. However， the expression level of nuclei AIF was increased at PE24 after a single bout eccentric exercise.