스테로이드 치료 후 회복기의 규칙적인 운동이 어린 쥐의 스테로이드 유발성 위축 Type II 근육에 미치는 영향

Abstract

-Effect of Regular Exercise during Recovery Period Following Steroid Treatment on the Atrophied Type II Muscles Induced by Steroid in Young Rats

Purpose: This study was conducted to determine whether low intensity regular exercise following dexamethasone treatment could attenuate steroid-induced muscle atrophy.

Method: 36 Wistar-rats(90-110g) were divided into six groups: control group(C), dexamethasone treatment group(D), sedentary group after normal sedentary period(C+S), sedentary group after dexamethasone treatment period(D+S), exercise group after normal sedentary period(C+E), and excercise group after dexamethasone treatment period(D+E). D, D+S, and D+E groups received dexamethasone injection(5mg/Kg) for seven days whereas C, C+S, and C+E groups received normal saline injection. Both C+E and D+E groups ran on a treadmill for 60 minutes/day(20minutes/4hours) at 15m/min and a 10°grade for seven recovery days. Result: Post-weight(body weight before muscle dissection) of D group significantly decreased by 16.03%, and that of D+E group significantly increased by 15.51% compared with pre-weight(body weight before steroid treatment). TypeⅡ muscle(plantaris and gastrocnemius) weights of D group were significantly lower than those of C group. Myofibrillar protein contents of typeⅡ muscles of D group tended to decrease comparing with C group. In D+E groups, body weights and relative weights of typeⅡ muscles(muscle weight(㎎)/post-weight(g)) tended to increase comparing with D+S group. Conclusion: It is suggested that steroid- induced muscle atrophy can be ameliorated through low intensity regular exercise after dexamethasone treatment.