J Korean Acad Nurs.  2007 Feb;37(1):81-90.

Effects of Exercise before Steroid Treatment on Type I and Type II Hindlimb Muscles in a Rat Model

• Choe MA
• An GJ

Abstract

PURPOSE: The purpose of this study was to examine the effects of daily exercise before steroid treatment on mass, the type I and II fiber cross-sectional area, and myofibrillar protein content of hindlimb muscles in a rat model. METHOD: Adult male Sprague-Dawley rats were randomly assigned to one of three groups: a control group(n=10) that had a normal saline injection for 7days, a steroid group(n=10) that had a steroid injection for 7days, and an exercise-steroid group(n=10) that ran on the treadmill for 7days before a steroid treatment. Body weight and food intake were measured every day. At 15 days all rats were anesthetized and the soleus, plantaris and gastrocnemius muscles were dissected. RESULT: The exercise-steroid group showed significant increases as compared with the steroid group in body weight, muscle weight of the soleus and gastrocnemius, type II muscle fiber cross-sectional area of plantaris, and myofibrillar protein content of the soleus, plantaris, and gastrocnemius. As compared with the control group, the steroid group showed significant decreases in body weight and diet intake, muscle weight, the type II fiber cross-sectional area and myofibrillar protein content of the soleus, plantaris, and gastrocnemius muscles. CONCLUSION: Daily exercise before steroid treatment attenuates hindlimb muscle atrophy, with type II muscle changes more apparent than type I muscle changes.

Keyword

Steroid; Exercise; Muscular atrophy; Type I and II fiber cross-sectional area; Myofibrillar protein content

MeSH Terms

Animals
Body Weight
Combined Modality Therapy
Dexamethasone/*therapeutic use
Disease Models, Animal
*Exercise Therapy
Hindlimb
Male
Muscle Contraction/drug effects
Muscle Fibers, Skeletal/*drug effects/physiology
Muscle, Skeletal/*drug effects/physiology
Muscular Atrophy/etiology/pathology/*therapy
Organ Size
Rats
Rats, Sprague-Dawley