Here it is what I found on another board:
Mechano Growth Factor (MGF)
Mechano Growth Factor (MGF):a local growth factor or a local tissue repair factor. MGF is derived from the insulin-like growth factor (IGF-1), but its sequence differs from the systemic IGF-1 produced by the liver. MGF is expressed as a form of IGF-1 by mechanically overloaded muscle when mechanical resistance is applied to muscles (such as weight training). At this point, the IGF-1 gene is spliced to produce IGF-1Ec (which is another name for MGF). It is expressed as a pulse following muscle damage and is apparently involved in the activation of muscle satellite cells[1]. This production of MGF can stimulate satellite cells into activation, to create new muscle fiber[2]. MGF also promotes nitrogen retention and new protein synthesis. It could actually be the case that this particular expression of MGF (IGF-1Ec) is an important part of the deciding factors in whether a muscle will grow or not. The introduction of this peptide, either by weight training or by an injection, will cause the affected area to respond by producing new muscle tissue. It would be safe to say that MGF presence in the muscle is one of the most major factors in the anabolic effect of resistance training (weight training). Currently, this compound is being used successfully by bodybuilders, for bringing up lagging body parts as well as overall growth.
Effects
MGF is being used successfully by bodybuilders, for bringing up lagging body parts as well as overall growth. The most relevant rodent data has been shown that MGF is a very potent inducer of muscle growth when it’s introduced into the muscle via an intramuscular injection of cDNA. In fact, in one study MGF caused a 20% increase in the weight of the injected muscle within 2 weeks[3]. Further investigation elucidated that this was actually due to an increase in the size of the muscle fibers[4].
Mechanism
MGF is extremely likely to cause myogenesis during skeletal muscle hypertrophy by contributing to at least by three important molecular processes: increased satellite cell activity, gene transcription and protein translation. Satellite cells in skeletal muscle provide the extra nuclei for postnatal growth[5] and that they are also involved in repair and regeneration following local injury of muscle fibers[6]. In normal adult undamaged tissue, the satellite cells are quiescent and usually detected just beneath the basal lamina. When activated, they commence to coexpress myogenic factors, including c-met, myoD, myf5, and, later, myogenin[7]. When introduced either by weight training or by an injection,MGF appears to stimulate satellite cells into activation. This in turn allows the activation of extra undamaged nuclei required for muscle fiber growth and repair to occur. In addition, the appearance of MGF initiates the upregulation of new protein synthesis. After this initial and short lived burst of splicing, IGF-1 production switches towards producing a systemic release of IGF-1Ea from the liver, which upregulates protein synthesis as well, but over a longer time line. During this process of regenerating muscle, myoblasts are formed to replace and hypercompensate for damaged/destroyed ones, and then theycan either fuse with each other to form totally new myofibers or becomeincorporated into previously damaged (surviving) myofibers. Ultimately, if more myofibers are created than were destroyed (by training) new muscle growth is experienced.
Dosage and Administration
It’s a good way for bodybuilders and other athletes to increase muscle weight by shooting MGF immediately post workout. At this point natural levels of MGF are already elevated. The addition of extra MGF should push more satellite cells towards the formation of new muscle tissue. Administration dosage of MGF should be at about 100mcgs/day, which is injected into the primary muscle trained post workout - half going into that muscle on one side of the body, the other half going into the mirror image of that muscle on the other side. We suggest that a administration of IGF-1, such as IGF-1 Long R3, an hour after shooting of MGF will produce the additional activation of satellite cells, protein translation, and gene transcription. It will force the body to produce much more new tissue than if MGF or IGF are used at any other point during the day, or in a different sequence. It seems that MGF and IGF-1 appear to act synergistically and promote rapid new muscle growth.
Although MGF is a fairly new peptide, recent studies drawing the comparison between IGF-1 and MGF have concluded that MGF is even quicker to produce results. Actually, it’s been found in rodent studies to produce both faster and better results with regards to muscle growth, compared to IGF-1[11]. It has been found by Goldspink G.’group that a single intramuscular injection of MGF cDNA into a mouse muscle resulted in a 25% increase in mean muscle fibre cross section area within three weeks[12]. Similar experiments have been carried out using the systemic or liver type of IGF-1 in an adenoviral vector under the control of a muscle regulatory sequence. However, this took four months to produce a 15% increase and is probably due to the anabolic effect of IGF-1, which is common to all the splice variants[13]. So far as we know, MGF is superior to IGF-1 and HGH for bodybuilders as an anabolic agent and this compound is being used successfully by bodybuilders, for bringing up lagging body parts as well as overall growth.
References
* Hill M and Goldspink G. Expression and splicing of the insulin-like growth factor gene in rodent muscle is associated with muscle satellite (stem) cell activation following local tissue damage. J Physiol 549: 409–418, 2003.
* Yang SY and Goldspink G. Different roles of the IGF-I Ec peptide (MGF) and mature IGF-I in myoblast proliferation and differentiation. FEBSLett 522: 156–160, 2002.
* Goldspink G. Skeletal muscle as an artificial endocrine tissue[J].Best Pract Res Clin Endocrinol Metab, 17(2):211-222, 2003.
* Hill M,Wernig A, Goldspink G. Muscle satellite (stem) cell activation during local tissue injury and repair. J Anat, 203 (1): 89 -99, 2003.
* Moss FP and Leblond CP. Satellite cells are the source of nuclei in muscles of growing rats. Anat Rec 170: 421–435,1970.
* Grounds MD. Age-associated changes in the responses of skeletal muscle cells to exercise and regeneration. Ann NY Acad Sci 854: 78–91, 1998.
* Qu-Petersen Z, Deasy B, Jankowski R, Ikezawa M, Cummins J, Pruchine R, Mytinger J, Cao B, Gates C, Wernig A, and Huard J. Identification of a novel population of muscle stem cells in mice: potential for muscle regeneration. J Cell Biol 175: 851–864, 2002.
* Adams and McCue. Localized infusion of IGF-I results in skeletal muscle hypertrophy in rats J Appl Physiol , 84(5): 1716-1722, 1998
* Hameed, M., Orrell, R. W., Cobbold, M., Goldspink, G., Harridge, S. D. R. Expression of IGF-I splice variants in young and old human skeletal muscle after high resistance exercise. J Physiol. 547: 247-254, 2003.
* G. GoldspinkMechanical Signals, IGF-I Gene Splicing, and Muscle AdaptationPhysiology, August 1, 20(4): 232 – 238, 2005.
* Mechanical signals and IGF-I gene splicing in vitro in relation to development of skeletal muscle. J Cell Physiol. 202 (1):67-75, 2005.
* Goldspink G, Yang SY. Method of treating muscular disorders. United States Patent. Patent No US 6,221,842 B1, Apr 24, 2001.
* Barton-Davis E, Shoturma DI, Musaro A, et al. Viral mediated expression of insulin-like growth factor-I blocks the aging-related loss of skeletal muscle function. Proc Natl Acad Sci USA. 95:15603–7, 1998.