Does MGF inlarge the digestive tract?

0o0o0o · Apr 7, 2009

0o0o0o · Jun 16, 2009

Ok no one has replied to this one, but Ive concluded it does because it acts as IGF out side of the cell.

Thewhite9t · Jun 19, 2009

0o0o0o said:
Ok no one has replied to this one, but Ive concluded it does because it acts as IGF out side of the cell.

MGF only exists in skeletal muscle. It's primary purpose is not making cells bigger, it's building new muscle cell nuclei. This is what it was designed for and one of the reasons it's promising although I have not seen anyone who says they were amazed at the results. As I've heard it's best used as a supplement to IGF-1R3.

gridlock · Jun 19, 2009

0o0o0o said:
Does MGF inlarge the digestive tract?

no it doesnt. igf receptors are present in digestive tract so IGF travelling in the blood will naturally be drawn to it. MGf receptors dont exist.

Put it in the correct forum next time and people will answer

biochemist · Jun 22, 2009

gridlock1983 said:
MGf receptors dont exist.

Do you have a source on this?

I haven't seen a single piece of literature documenting the existence or lack of existence for one. It has to act on something...

jm425 · Jun 22, 2009

Actually dat has said that mgf receptors don't exist and it is true. Only igf receptors exist and I believe that mgf is used by the igf receptors. Remember, mgf is a form of igf. Also, the reason why people don't rave of mgf results is because they don't use a high enough dose all at once into the muscles. IMO, a very high dose needs to be administered after workout to see results.

biochemist · Jun 23, 2009

I am aware of where MGF comes from. Unless datbtrue is working alongside one of the few researchers in the world that is publishing data on MGF, I would be very suspicious of his statements. Peptides generally have receptors (this is what nature uses them for), and it would be very unlikely that MGF transduced signals through the IGF-1 receptor due to their vastly different primary sequence and secondary structures. Hence something else is probably at play.

It is also important to remember that MGF was only discovered in the past 10 years and not a lot of work has been done examining its biology. IGF-1 has been studied for much longer.

But to exemplify the lack of knowledge the field has on this hormone, look towards this recent publication that merely examines to see if MGF acts through the same pathways as IGF-1:

Mol Med. 2009 Mar 19.
IGF-1 Expression in Infarcted Myocardium and MGF E Peptide Actions on Rat Cardiomyocytes, In Vitro.
Stavropoulou A, Halapas A, Sourla A, Philippou A, Papageorgiou E, Papalois A, Koutsilieris M.

Department of Experimental Physiology, MedicalSchool, National Kapodistrian University of Athens, Goudi-Athens, Greece.

Insulin-like growth factor-1 (IGF-1) expression is implicated in myocardial pathophysiology and two IGF-1 mRNA splice variants have been detected in rodents, namely the IGF-1Ea and the mechano-growth factor (MGF). Consequently, we have investigated the expression pattern of the IGF-1 gene transcripts in rat myocardium after left anterior descending coronary artery ligation-induced myocardial infarction (1hr up to 8wks). In addition, we characterized IGF-1 and MGF E peptide action and their respective signaling in H9C2 myocardial-like cells, in vitro. IGF-1Ea and MGF expression were significantly increased, both at transcriptional and translational level, during the late post-infarction period (4wks and 8wks) in infracted rat myocardium. Measurements of serum IGF-1 levels in infracted rats were initially decreased (24hr up to 1wk) but remained unaltered throughout the late experimental phase (4wks to 8wks) as compared to this of sham-operated rats. Furthermore, specific anti-IGF-1R neutralizing antibody failed to block the synthetic MGF E peptide action while it blocked completely IGF-1 action on the proliferation of H9C2 cells. Moreover, this synthetic MGF E peptide did not activate Akt phosphorylation while it activated ERK1/2 in H9C2 rat myocardial cells. These data support the role of IGF-1 expression in myocardial repair process and suggest that synthetic MGF E peptide actions are mediated possibly via an IGF-1R independent pathway in rat myocardial cells, as suggested by our in vitro experiments.

-------------------------------

Notice they say no Akt phosphorylation occurred (a hallmark of IGF-1 signaling) whereas ERK1/2 were activated. ERK1/2 activation would suggest the activity of a yet-to-be-identified GPCR.

gridlock · Jun 23, 2009

biochemist said:
I am aware of where MGF comes from. Unless datbtrue is working alongside one of the few researchers in the world that is publishing data on MGF, I would be very suspicious of his statements. Peptides generally have receptors (this is what nature uses them for), and it would be very unlikely that MGF transduced signals through the IGF-1 receptor due to their vastly different primary sequence and secondary structures. Hence something else is probably at play.

It is also important to remember that MGF was only discovered in the past 10 years and not a lot of work has been done examining its biology. IGF-1 has been studied for much longer.

But to exemplify the lack of knowledge the field has on this hormone, look towards this recent publication that merely examines to see if MGF acts through the same pathways as IGF-1:

Mol Med. 2009 Mar 19.
IGF-1 Expression in Infarcted Myocardium and MGF E Peptide Actions on Rat Cardiomyocytes, In Vitro.
Stavropoulou A, Halapas A, Sourla A, Philippou A, Papageorgiou E, Papalois A, Koutsilieris M.

Department of Experimental Physiology, MedicalSchool, National Kapodistrian University of Athens, Goudi-Athens, Greece.

Insulin-like growth factor-1 (IGF-1) expression is implicated in myocardial pathophysiology and two IGF-1 mRNA splice variants have been detected in rodents, namely the IGF-1Ea and the mechano-growth factor (MGF). Consequently, we have investigated the expression pattern of the IGF-1 gene transcripts in rat myocardium after left anterior descending coronary artery ligation-induced myocardial infarction (1hr up to 8wks). In addition, we characterized IGF-1 and MGF E peptide action and their respective signaling in H9C2 myocardial-like cells, in vitro. IGF-1Ea and MGF expression were significantly increased, both at transcriptional and translational level, during the late post-infarction period (4wks and 8wks) in infracted rat myocardium. Measurements of serum IGF-1 levels in infracted rats were initially decreased (24hr up to 1wk) but remained unaltered throughout the late experimental phase (4wks to 8wks) as compared to this of sham-operated rats. Furthermore, specific anti-IGF-1R neutralizing antibody failed to block the synthetic MGF E peptide action while it blocked completely IGF-1 action on the proliferation of H9C2 cells. Moreover, this synthetic MGF E peptide did not activate Akt phosphorylation while it activated ERK1/2 in H9C2 rat myocardial cells. These data support the role of IGF-1 expression in myocardial repair process and suggest that synthetic MGF E peptide actions are mediated possibly via an IGF-1R independent pathway in rat myocardial cells, as suggested by our in vitro experiments.

-------------------------------

Notice they say no Akt phosphorylation occurred (a hallmark of IGF-1 signaling) whereas ERK1/2 were activated. ERK1/2 activation would suggest the activity of a yet-to-be-identified GPCR.

Ok perhaps my bad on the non existence but it is yet to be found. when tests have been done with IGF and MGf being run concurrently, they haven't competed for receptors despite the fact they both use the same pathway.

biochemist · Jun 24, 2009

gridlock1983 said:
when tests have been done with IGF and MGf being run concurrently, they haven't competed for receptors despite the fact they both use the same pathway.

What tests are you referring to?

Given what this publication states, there could be subtle differences in what IGF-1 and MGF are able to achieve in terms of muscle growth. The fact that MGF does not induce Akt phosphorylation but rather ERK1/2 may signal that either both are needed for optimal muscle recovery or that they instill different biological processes all together, and pending what sort of trauma is provided to the muscle, you may need/want more of one or the other or both to recover. MGF is a very interesting peptide though, there should be a lot more to come from it in the future.

FYI: Paper full text is available for free: http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=2656994&blobtype=pdf

gridlock · Jun 24, 2009

biochemist said:
What tests are you referring to?

Given what this publication states, there could be subtle differences in what IGF-1 and MGF are able to achieve in terms of muscle growth. The fact that MGF does not induce Akt phosphorylation but rather ERK1/2 may signal that either both are needed for optimal muscle recovery or that they instill different biological processes all together, and pending what sort of trauma is provided to the muscle, you may need/want more of one or the other or both to recover. MGF is a very interesting peptide though, there should be a lot more to come from it in the future.

FYI: Paper full text is available for free: http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=2656994&blobtype=pdf

trying to find it now for you.

I've got this in my notes section in outlook but cant find the site i nicked it from. it just outlines that igf and mgf wont compete for receptors. if i can find the rest i'll post it up. saying that i think Dat has posted stuff on here about it

The physiological function of MGF was studied using an in vitro cell model. Unlike IGF-I, the distinct E domain of MGF inhibits terminal differentiation whilst increasing myoblast proliferation. Blocking the IGF-I receptor with a specific antibody indicated that the function of MGF E domain is mediated via a different receptor. The results provide a basis for localized tissue adaptation and helps explain why loss of muscle mass occurs in the elderly and in dystrophic muscle in which MGF production is markedly affected (Yang SY, Goldspink G., 2002, p. 156-60).

DatBtrue · Jun 24, 2009

biochemist; said:
I am aware of where MGF comes from. Unless datbtrue is working alongside one of the few researchers in the world that is publishing data on MGF, I would be very suspicious of his statements.