Sarcopenia는 노화로 인한 점진적인 골격근량과 근력의 감소로 정의된다, Sarcopenia로 인한 근위축의 특징 중 하나는 type ll fast glycolytic 섬유의 감소가 가속화되는 것이다. Dexamethasone은 Glucocorticoid와 유사한 생리활성을 나타내는 약물로써, 골격근에 근위축 발생과 함께 Myosin heavy chain(MyHC)를 Fast to Slow로 ...
Sarcopenia는 노화로 인한 점진적인 골격근량과 근력의 감소로 정의된다, Sarcopenia로 인한 근위축의 특징 중 하나는 type ll fast glycolytic 섬유의 감소가 가속화되는 것이다. Dexamethasone은 Glucocorticoid와 유사한 생리활성을 나타내는 약물로써, 골격근에 근위축 발생과 함께 Myosin heavy chain(MyHC)를 Fast to Slow로 transition 시킨다. Young Group (4개월령)과 Aged Group (22개월령)에서 체중, 전경골근 (TA) 무게, 평균 근섬유 굵기, 근섬유 속성에 따른 근섬유 굵기와 MyHC transition을 Dexamethasone을 7일간 투여한 근위축기와 (Dex: 2 mg/kg Young; 0.5 mg/kg Aged, DEX-injection)와 중단 후 7일 후 회복기 (DEX-recovery)에서 각각 관찰하였다. DEX-injection은 Control과 비교하여 Young group과 Aged group 모두 유의한 체중, 전경골근 무게, 근섬유 굵기의 유의한 감소와 Fast to Slow MyHC transition이 나타났다. DEX-recovery와 DEX-injection를 비교하였을 때, Young group은 체중, 전경골근 무게, 근섬유 굵기가 유의하게 증가되었으나, Aged Group은 DEX-recovery에서 유의한 증가를 나타내지 않았다. 또한 Young group은 Slow to Fast로 MyHC transition이 되었지만, Aged Group에서는 근위축으로 인한 Fast to Slow가 지속되었다. 이러한 결과들은 노화된 근육은 근위축이 진행된 후 MyHC transition은 다른 요인들보다 오랜 기간 근위축이 진행되는 것을 알 수 있다. 그렇기 때문에 노화된 골격근에서 MyHC transition회복을 위한 적절한 중재의 필요성을 제안한다.
Sarcopenia는 노화로 인한 점진적인 골격근량과 근력의 감소로 정의된다, Sarcopenia로 인한 근위축의 특징 중 하나는 type ll fast glycolytic 섬유의 감소가 가속화되는 것이다. Dexamethasone은 Glucocorticoid와 유사한 생리활성을 나타내는 약물로써, 골격근에 근위축 발생과 함께 Myosin heavy chain(MyHC)를 Fast to Slow로 transition 시킨다. Young Group (4개월령)과 Aged Group (22개월령)에서 체중, 전경골근 (TA) 무게, 평균 근섬유 굵기, 근섬유 속성에 따른 근섬유 굵기와 MyHC transition을 Dexamethasone을 7일간 투여한 근위축기와 (Dex: 2 mg/kg Young; 0.5 mg/kg Aged, DEX-injection)와 중단 후 7일 후 회복기 (DEX-recovery)에서 각각 관찰하였다. DEX-injection은 Control과 비교하여 Young group과 Aged group 모두 유의한 체중, 전경골근 무게, 근섬유 굵기의 유의한 감소와 Fast to Slow MyHC transition이 나타났다. DEX-recovery와 DEX-injection를 비교하였을 때, Young group은 체중, 전경골근 무게, 근섬유 굵기가 유의하게 증가되었으나, Aged Group은 DEX-recovery에서 유의한 증가를 나타내지 않았다. 또한 Young group은 Slow to Fast로 MyHC transition이 되었지만, Aged Group에서는 근위축으로 인한 Fast to Slow가 지속되었다. 이러한 결과들은 노화된 근육은 근위축이 진행된 후 MyHC transition은 다른 요인들보다 오랜 기간 근위축이 진행되는 것을 알 수 있다. 그렇기 때문에 노화된 골격근에서 MyHC transition회복을 위한 적절한 중재의 필요성을 제안한다.
Sarcopenia is primarily defined as a progressive loss of muscle mass and muscle strength resulting from the aging process. Muscle fiber atrophy in sarcopenia is one of characterized by an accelerating loss of type II fast glycolytic fibers. Dexamethasone is a drug that mimics glucocorticoid-like phy...
Sarcopenia is primarily defined as a progressive loss of muscle mass and muscle strength resulting from the aging process. Muscle fiber atrophy in sarcopenia is one of characterized by an accelerating loss of type II fast glycolytic fibers. Dexamethasone is a drug that mimics glucocorticoid-like physiology, leading to muscle atrophy and Fast to Slow myosin heavy chain (MyHC) transition. The MyHC isoform transition in Young (~4 months) and Aged (~22 months) Group was examined both during dexamethasone injection (DEX-injection; 2 mg/kg in Young Group; 0.5 mg/kg in Aged Group; for 7 days) and after the discontinuation thereof (DEX-recovery; for 7 days) in tibialis anterior (TA). Body weights, tibialis anterior muscle weights and Cross section area in the DEX-injection period in both the Young group and Aged group were significantly lower than that in the control group. Also Fast to Slow MyHC transition (type IIb → IIx → IIa → I) was observed in both age groups. During the DEX-recovery period, muscle atrophy was restored in young group, but not in aged group. Also muscle fiber type changed from slow-to-fast MyHC isoform (type l → type lla → type llx → type llb) only in Young group.
The results were as follows.
1. Body weight and TA muscle weight were not different between the DEX-injection and the DEX-recovery period in the Aged Group. 2. Average cross section area were not significantly increased between the DEX-injection and the DEX-recovery period in Aged Group. 3. cross section area of muscle fiber types were not different between the DEX-injection and the DEX-recovery period in the Aged Group. 4. Transition of MyHC in the TA muscle during the DEX-injection significantly increased type llx and decreased Type llb, and during the DEX-recovery significantly increased type llx in the Aged Group.
These results suggest that aged skeletal muscle obtained rapidly aged skeletal muscle may experience difficulty in restoration during and after atrophic conditions and suggests that muscle atrophy in the elderly is necessarily need to be proper prevented.
Sarcopenia is primarily defined as a progressive loss of muscle mass and muscle strength resulting from the aging process. Muscle fiber atrophy in sarcopenia is one of characterized by an accelerating loss of type II fast glycolytic fibers. Dexamethasone is a drug that mimics glucocorticoid-like physiology, leading to muscle atrophy and Fast to Slow myosin heavy chain (MyHC) transition. The MyHC isoform transition in Young (~4 months) and Aged (~22 months) Group was examined both during dexamethasone injection (DEX-injection; 2 mg/kg in Young Group; 0.5 mg/kg in Aged Group; for 7 days) and after the discontinuation thereof (DEX-recovery; for 7 days) in tibialis anterior (TA). Body weights, tibialis anterior muscle weights and Cross section area in the DEX-injection period in both the Young group and Aged group were significantly lower than that in the control group. Also Fast to Slow MyHC transition (type IIb → IIx → IIa → I) was observed in both age groups. During the DEX-recovery period, muscle atrophy was restored in young group, but not in aged group. Also muscle fiber type changed from slow-to-fast MyHC isoform (type l → type lla → type llx → type llb) only in Young group.
The results were as follows.
1. Body weight and TA muscle weight were not different between the DEX-injection and the DEX-recovery period in the Aged Group. 2. Average cross section area were not significantly increased between the DEX-injection and the DEX-recovery period in Aged Group. 3. cross section area of muscle fiber types were not different between the DEX-injection and the DEX-recovery period in the Aged Group. 4. Transition of MyHC in the TA muscle during the DEX-injection significantly increased type llx and decreased Type llb, and during the DEX-recovery significantly increased type llx in the Aged Group.
These results suggest that aged skeletal muscle obtained rapidly aged skeletal muscle may experience difficulty in restoration during and after atrophic conditions and suggests that muscle atrophy in the elderly is necessarily need to be proper prevented.
주제어
#Sarcopenia, Dexamethasone, Myosin heavy chain transition, Muscle atrophy
학위논문 정보
저자
김영민
학위수여기관
경희대학교 동서의학대학원
학위구분
국내석사
학과
노인학과노년학전공
지도교수
맹성호
발행연도
2018
총페이지
ii, 34 p.
키워드
Sarcopenia, Dexamethasone, Myosin heavy chain transition, Muscle atrophy
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