Int Neurourol J.  2014 Jun;18(2):77-85.

Aerobic Exercise Affects Myostatin Expression in Aged Rat Skeletal Muscles: A Possibility of Antiaging Effects of Aerobic Exercise Related With Pelvic Floor Muscle and Urethral Rhabdosphincter

• Ko IG
• Jeong JW
• Kim YH
• Jee YS
• Kim SE
• Kim SH
• Jin JJ
• Kim CJ
• Chung KJ

Abstract

PURPOSE
Aging-induced loss of muscle mass and subsequent reduction of strength is a fundamental cause of frailty, functional decline, and disability. And this may lead to muscular dysfunction, voiding dysfunction, or urinary incontinence due to pelvic muscle weakness induced by aging. Physical exercise has been recommended for the prevention and the treatment of these age-related frail states. We investigated the effects of treadmill exercise on muscle strength, myostatin mRNA and protein expression, and gastrocnemius myocytes proliferation in aged rats to investigate the possible antiaging effects of aerobic exercise on skeletal muscles such as pelvic floor muscles and urethral rhabdosphincter muscle.
METHODS
In this study, 5-month-old male Sprague-Dawley rats were used as the young-age group (n=20) and 24-month-old rats were used as the old-age group (n=20). Each group was randomly divided into two groups (n=10 in each group): the sedentary and the treadmill exercise group. The rats in the exercise groups were forced to run on a motorized treadmill for 30 minutes, once a day, for 6 weeks. For this study, a weight load test, hematoxylin and eosin staining, real-time and reverse transcription polymerase chain reaction for myostatin mRNA, myostatin western blot, and 5-bromo-2'-deoxyuridine immunohistochemistry were performed in the gastrocnemius muscle.
RESULTS
The age-induced reduction of muscle mass and strength was associated with a decrease in myocyte proliferation and an increase in myostatin mRNA and protein expression in the gastrocnemius. However, treadmill exercise improved muscle mass and strength through suppression of myostatin mRNA and protein expression, and myocyte proliferation increase in the gastrocnemius against the aging process.
CONCLUSIONS
Aerobic exercise is a useful strategy for enhancing muscle function against aging-induced loss of skeletal muscle mass and functions.

Keyword

Aging; Exercise; Myostatin; Skeletal muscle; Muscle cell

MeSH Terms

Aging
Animals
Blotting, Western
Bromodeoxyuridine
Child, Preschool
Eosine Yellowish-(YS)
Exercise*
Hematoxylin
Humans
Immunohistochemistry
Infant
Male
Muscle Cells
Muscle Strength
Muscle Weakness
Muscle, Skeletal*
Muscles
Myostatin*
Pelvic Floor*
Polymerase Chain Reaction
Rats*
Rats, Sprague-Dawley
Reverse Transcription
RNA, Messenger
Urinary Incontinence
Bromodeoxyuridine
Eosine Yellowish-(YS)
Hematoxylin
Myostatin
RNA, Messenger