운동강도의 차이가 60주령된 흰쥐의 Soleus와 EDL에서 Bcl-2, Bax, caspase-3와 DNA 절편화에 미치는 영향 (Effects of Exercise Intensity on Bcl-2, Bax, Caspase-3 Protein Level and DNA Fragmentation in Soleus and EDL Muscle on 60 wk SD Rats)

서지정보

· 발행기관 : 한국생명과학회
· 수록지 정보 : 생명과학회지 / 20권 / 4호 / 572 ~ 577페이지
· 저자명 : 이지영, 김용안

초록

본 연구에서 60 주령된 쥐를 대상으로 8 주간 트레드밀 운동강도와 근섬유 유형에 따른 apoptosis 관련 인자를 연구하였다. 결론적으로 노후된 쥐의 apoptosis 관련 인자는 운동강도와 근육유형에 따라 차이가 났다. EDL이 Soleus보다 apoptosis인자의 변화가 운동강도에 의해 더 민감하게 나타났다. 또한 casepase-3의 발현은 고강도 운동에서 나타났으나 DNA 절편화는 나타나지 않았기에 실질적인 apoptosis는 발생되지 않았다. 이는 노후된 개체의 운동 수행방법으로 고강도 운동은 적합하지 않으며, 고강도 운동상태를 지속할 경우 근섬유의 apoptosis를 유도할 가능성이 있다는 것을 시사한다. 그러므로 추후 실험에서는 운동시간과 빈도에 의한 apoptosis의 timecourse impact 관찰과 외재적 경로(caspase independent apoptosis)에서의 apoptosis 관련 단백질 변화에 대한 연구를 통하여 노화에 의한 근손실의 원인 규명이 요구된다.

영어초록

The purpose of this study was to find out the Bcl-2 (B-cell leukemia/lymphoma-2), Bax, and caspase-3 (cysteine-aspartic proteases-3) protein expression in soleus and EDL muscle according to treadmill exercise intensity in 60 week-old SD rats. The SD rats were randomly divided into four groups (n=10 in each group): control (CON), low intensity exercise (LE), moderate intensity exercise (ME), and high intensity exercise (HE). The exercise was given to the rats for 8 wk, 5 day/wk. The animals underwent treadmill exercise at intensities of 30 min at 8 m/min for the LE group, 15 min at 16 m/min for the ME group, and 9 min at 24 m/min for the HE group. The results were as follows: the expression of Bcl-2 protein was lowest in the HE group and the expression of Bax protein was highest in the HE group. The expression of caspase-3 (cleaved form) protein was observed in the HE group. For the different types of muscle fiber, Bcl-2 protein expression in the soleus muscle was decreased in all groups. Bax protein expression in the soleus muscle was increased in the HE group only. Bcl-2 protein expression in the EDL muscle was decreased in the HE group, and Bax protein expression in the EDL muscle was increased in the ME and HE groups. Consequently, the protein expression related to the aged rats shows a difference according to the intensity of exercise. In addition, caspase-3 protein expression appeared in the HE group; however, in all amounts of intensity, DNA fragmentation was not observed. Therefore, apoptosis on skeletal muscles of aged mice can be intervened with optimal exercise. On the other hand, high intensity exercise can potentially accelerate the apoptosis of muscle fiber in aged rats.

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