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Mechano Growth Factor (MGF): The Most Powerful Anabolic Growth Factor Ever? PDF Print E-mail
Written by Robbie Durand   
Thursday, 08 January 2009
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Mechano Growth Factor (MGF): The Most Powerful Anabolic Growth Factor Ever?
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What Happens IF MGF is Injected?
 It was interesting that when researchers compared resting levels of MGF in young and older men, there was no difference at rest. However, MGF expresses much more MGF after a single bout of resistance exercise, which may be the reason younger men make larger gains in muscle mass than older men after an identical training regimen. The resting levels of MGF are 100-fold lower than muscle-liver mediated IGF-1.7 MGF is only expressed in response to muscle damage, but if a bodybuilder were to inject MGF…well, let’s just say there would probably be some kick-ass muscle growth, as MGF not only activates satellite cells, but also upregulates protein synthesis in muscle.

One study showed that the basal levels of MGF in muscle were directly related to muscle cross-sectional area (how big your muscles are).10 A leading pioneer in MGF research, Dr. Goldspink, noted that although his research has much more to learn about MGF, gene therapy has advantages over injecting the MGF peptide, as the peptide version would have to be administered more often.13 Dr. Goldspink has recommended that MGF, rather than the liver-muscle form of IGF-1, be used as a generic therapeutic agent for muscle wasting. Another big advantage that MGF has is that once injected into a muscle, it has direct anabolic actions that are site specific, without the worry of affecting other organs such as the prostate (as testosterone does). More human research needs to be conducted with MGF injections as only animal studies have been conducted, but the animal studies are impressive so far.

References:
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7.    Hameed M, Orrell RW, Cobbold M, Goldspink G, Harridge SD. Expression of IGF-I splice variants in young and old human skeletal muscle after high resistance exercise. J Physiol, 2003 Feb 15;547(Pt 1):247-54.
8.    Goldspink G. Mechanical signals, IGF-I gene splicing and muscle adaptation. Physiology (Bethesda), 2005 Aug;20:232-8. Review.
9.    Heinemeier KM, Olesen JL, Schjerling P, Haddad F, Langberg H, Baldwin KM, Kjaer M. Short-term strength training and the expression of myostatin and IGF-I isoforms in rat muscle and -tendon: Differential effects of specific contraction types. J Appl Physiol, 2006 Oct 12.
10.    Hameed M, Lange KH, Andersen JL, Schjerling P, Kjaer M, Harridge SD, Goldspink G. The effect of recombinant human growth hormone and resistance training on IGF-I mRNA expression in the muscles of elderly men. J Physiol, 2004 Feb 15;555(Pt 1):231-40.
11.    Barton-Davis ER, Shoturma DI, Musaro A, Rosenthal N, Sweeney HL. Viral mediated expression of insulin-like growth factor I blocks the aging-related loss of skeletal muscle function. Proc Natl Acad Sci USA, 1998 Dec 22;95(26):15603-7.
12.    Goldspink G, Yang SY. The splicing of the IGF-I gene to yield different muscle growth factors. Adv Genet, 2004;52:23-49. Review.
13.    Goldspink G. Impairment of IGF-I gene splicing and MGF expression associated with muscle wasting. Int J Biochem Cell Biol, 2006 Mar;38(3):481-9. Review.
14.    Owino V, Yang SY, Goldspink G. Age-related loss of skeletal muscle function and the inability to express the autocrine form of insulin-like growth factor-1 (MGF) in response to mechanical overload. FEBS Lett, 2001 Sep 14;505(2):259-63.
15.    Yakar S, Liu JL, Stannard B, Butler A, Accili D, Sauer B, LeRoith D. Normal growth and development in the absence of hepatic insulin-like growth factor. I Proc Natl Acad Sci USA, 1999 Jun 22;96(13):7324-9.
16.    Kim JS, Cross JM, Bamman MM. Impact of resistance loading on myostatin expression and cell cycle regulation in young and older men and women. Am J Physiol Endocrinol Metab, 2005 Jun;288(6):E1110-9.
17.    Yang SY, Goldspink G. Different roles of the IGF-I Ec peptide (MGF) and mature IGF-I in myoblast proliferation and differentiation. FEBS Lett, 2002 Jul 3;522(1-3):156-60. Erratum in: FEBS Lett, 2006 May 1;580(10):2530.
18.    Berg U, Bang P. Exercise and circulating insulin-like growth factor.s I Horm Res, 2004;62 Suppl 1:50-8. Review.
19.    Sinha-Hikim I, Cornford M, Gaytan H, Lee ML, Bhasin S. Effects of testosterone supplementation on skeletal muscle fiber hypertrophy and satellite cells in community-dwelling older men. J Clin Endocrinol Metab, 2006 Aug;91(8):3024-33.



 
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