This article will dive into the compound known as “Follistatin” and to understand its full spectrum of possibilities we must dive into the topic of “Myostatin” as well. I hope by the end of this article you (the reader) may have a better understanding of not just what follistatin is, but how it can help your research and how it interacts with other compounds as well.
First things first… What is follistatin?
Follistatin is an autocrine glycoprotein that is found in nearly all tissues of mammals. It makes contact with the endocrine cells of the anterior pituitary including gonadotrophs and its initial isolation was from follicular fluid and then later synthesized at a high purity peptide for research (What we offer at our shop).
The source of follistatin in the blood has yet to be found, but it is speculated that the endothelial cells lining blood vessels, and/or the macrophages and monocytes circulating within the blood may be sources for follistatin. Although this may seem to imply we do not know much about follistatin, this is not the case. Researchers all over the world have begun researching this beautiful peptide and more and more data keeps rolling in on just how effective follistatin can be in research geared towards increasing muscle mass and/or limiting muscle loss under various conditions.
Follistatin administration has been repeatedly noted in research to inhibit myostatin and positively affect muscle growth. It has been found that increasing the amount of follistatin in the blood also “greatly increased muscle mass” and showed “increases in strength”. It was also noted that “by leading to increased muscle mass of certain core muscular groups, it can increase life expectancy in cases of spinal muscular atrophy (SMA) in animal models.”
Inhibit myostatin? What is myostatin and why is its inhibition potentially important?
Myostatin is known as “a member of the TGF-β family and functions as a negative regulator of muscle growth and it’s inhibition increases muscle mass and strength.” It is the only known protein secreted in the body that has been shown to have a negative effect in regulating muscle mass. By “negative effect” I mean shown to limit muscle growth and it does not necessarily mean it is an unwanted action, it has its place in the physical process. Myostatin “negatively regulates the proliferation and differentiation of muscle cells that promote muscle growth and repair” and by inhibiting myostatin with follistatin administration we now open doors to many possibilities geared towards enhancing muscle tissue growth, preserving muscle mass under complicated conditions and even possible anti-inflammatory effects as well, which I will touch on shortly. Follistatin research also helps us gather a better understanding of myostatins (or lack thereof) actions in the body.
Another compound worth some mention here in relation to follistatin is “Activin”. Follistatin antagonizes the actions of activin. Activin is “a member of the transforming growth factor beta (TGF)-β family and inhibits hepatocyte growth” and plays a big role in cellular proliferation and makes follistatin a “safeguard against uncontrolled cellular proliferation and also allowing it to function as an instrument of cellular differentiation.” This is a great importance because both play a very critical role in tissue rebuilding and repair. It is suspected this is the reason for follistatin's high presence in skin tissues.
Activin also plays a role in the inflammatory response following injury and it has been shown that the neutralising actions of follistatin on activin; “reduce the inflammation and mortality in several disease models.” Which I find quite interesting and leads me to believe there is an avenue for researching follistatin and its possible anti-inflammatory effects in the body.
Most researchers’ main area if interest with follistatin seem to be muscle mass enhancement, it has proven pretty impressive in this area. In one study conducted with follistatin it was noted; “resulted in significantly larger gastrocnemius and triceps muscles- we observed a more modest increase in muscle weight between 20 and 25%, muscle weights were increased by 194–327% relative to control animals, resulting from a combination of hyperplasia (66% increase in fiber number to 13,051 in the gastrocnemius/plantaris) and hypertrophy (28% increase in fiber diameter to 55 μm)”. It is also interesting to have noted that part of the positive effects of follistatin “may result from inhibition of another ligand besides myostatin”. Follistatin has also been shown to “decrease apoptosis, such as in cases of ischemic cardiac diseases.” Follistatins cardio protective properties are being noted more and more often, again just another of many possible areas of research with this amazing compound.
It has also been stated by researchers that an imbalance of stem cell activating and inhibitory signals to be a key marker of “age-related regenerative decline” and points to follistatin as a possible candidate to shift the balance towards renewal in older research subjects.
Follistatin also plays a role in metabolism and differentiation of fat cells, specifically during brown fat differentiation. It was noted by one researcher that “targeting TGF-β/Mst signaling enhances brown adipocyte functions and regulates energy balance, reducing insulin resistance, and curbing the development of obesity and diabetes.” And another researcher also noted “reduced fat accumulation during high-fat feeding by 16%, and liver fat by 50%, as determined by MRI - Fstl3 mice displayed improved insulin sensitivity and muscle insulin signalling - Fstl3 over-expression regulates insulin and glucagon sensitivities through increased muscular insulin action, as well as increased hepatic glucagon sensitivity and pancreatic glucagon content”
Very interesting indeed!
It is clear follistatin plays many major roles in the body and is essential for skeletal muscle development. The intracellular signalling networks that regulate follistatin-induced effects are not that well understood making research of this amazing compound that much more interesting to explore. One thing noted time and time again is increased mass and/or less degeneration in research subjects. It is likely why most follistatin research is often geared towards increasing muscle mass, rightfully so!
I hope that this breakdown of follistatins potential research applications and its interactions with other compounds has given you a greater understanding of how this peptide may enhance your research outcomes.
We at ar-r carry only the highest research quality peptides and hope this article, along with our quality peptides brings your research experience to a whole new level!
Ref
1) Lee S-J (2007) Quadrupling Muscle Mass in Mice by Targeting TGF-ß Signaling Pathways. PLoS ONE 2(8): e789. doi:10.1371/journal.pone.0000789
'Mighty mice' made mightier | EurekAlert! Science News2) Regulation of myostatin activity and muscle growth Se-Jin Lee* and Alexandra C. McPherron
Regulation of myostatin activity and muscle growth3) Delivery of recombinant follistatin lessens disease severity in a mouse model of spinal muscular atrophyFerrill F. Rose, Virginia B. Mattis, Hansjörg Rindt and Christian L. Lorson
Delivery of recombinant follistatin lessens disease severity in a mouse model of spinal muscular atrophy4) Isolation and partial characterization of follistatin: a single-chain Mr 35,000 monomeric protein that inhibits the release of follicle-stimulating hormone.N Ueno, N Ling, S Y Ying, F Esch, S Shimasaki, and R Guillemin
Isolation and partial characterization of follistatin: a single-chain Mr 35,000 monomeric protein that inhibits the release of follicle-stimulating hormone.....coming soon 
