Effects Of Exercise On The Insulin-like Growth Factor-Ⅰ MRNA Expression And Muscle Satellite (Stem) Cell Configuration In Skeletal Muscle Of Rats

Insulin-like growth factor (IGF-I) produced by the liver and induced by growth hormone (GH), is a main systemic regulator of tissue mass during postnatal growth. Published work indicates that insulin-like growth factors are also involved in tissue maintenance and the prevention of cell death as general regulators of protein synthesis and the activation of muscle satellite (stem) cells that are required for local muscle repair.It is found that three types of IGF-I in human muscle which are derived from the IGF-I gene by alternative splicing. The expression of one of these that appears to be an autocrine/paracrine splice variant is only detectable after mechanical stimulation (MGF) and a systemic type (IGF-I Ea) that is produced by the liver and other tissue including muscle. The third isoform, IGF-I Eb, is thought to be predominately expressed in the liver and its role in muscle is still unknown.32 male SD rats were divided into 4 groups as control, exercise...