View Full Version : why should one understand MUSCLE HYERTROPHY (ALL NEWBITES) Part 1

01-15-2011, 02:47 AM
Before you can grow muscle, you must understand about muscle growth and anabolic. also known as "muscle synthesis". Muscle growth is actually a very complex process, there is much more to it than just building proteins from amino acids. The word muscle hypertrophy is the correct term for building skeletal muscle. To reach this it requires the fusion of new cells (called satellite cells), with the muscle fibers. Unlike normal muscle cells, these satellites cells regenerated through out your entire life. These cells serve as a functional units on their own, they provide necessary components to repair and rebuild damaged muscle cells. Most of the time they stay dormant in us on the outer surface of the muscle fibers, waiting for an injury or some type of trauma to trigger them into activation. (Much like cancer cells, waiting).

Once one of the above have trigger them off, they will divide and multiply, and form into myoblasts, (these are essentially donor cells that express myogenic genes). This stage is known as satellites cell proliferation. the myoblasts will then fuse with the muscle fibers donating their nuclei. this is the DIFFERENTIATION. The skeletal muscle cells then process more nuclei. when the nucli is increase it regulate more cytoplasm, which allows more actin and myosin, these are the two dominat contractile proteins in the skeletal muscle to be produced. This increases the size and protein content of the muscle cell. But keep in mind you are not increasing the muscle cell number with muscle hyertrophy. you are only increasing cell size and protein content. You can only do this by using satellite cells to do this. It has been said that myoblasts fuse together and form new muscle fibers, known as muscle hyperplasia. This and the other parts should point some of newbites in the right direction.

01-15-2011, 03:51 AM
thats cool. thx for the lesson

01-15-2011, 05:00 AM
so keep piss pounding dem muscles when we lift?

01-16-2011, 01:35 PM
S-myotrophin promotes the hypertrophy of skeletal muscle of mice in vivo.
Shiraishi S, Nakamura YN, Iwamoto H, Haruno A, Sato Y, Mori S, Ikeuchi Y, Chikushi J, Hayashi T, Sato M, Cassens RG, Ito T.
Laboratory of Chemistry and Technology of Animal Products, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-Ward, Fukuoka 812-8581, Japan.
S-myotrophin is a newly discovered muscle growth factor. Effects of crude S-myotrophin injection on the growth and morphology of skeletal muscle of normal, ScN and mdx mice were investigated in the present study. Total dose of crude S-myotrophin was 100 microg (100 microg protein/ml x 50 microl x 20 times). In the case of normal mice (Sea:ddY), body weight and the weight of M. gluteus major of crude S-myotrophin injected mice was significantly heavier than that of control (PBS-injected) mice after 5 weeks' feeding. Antibody staining of laminin and dystrophin showed clear sarcolemmal and basement membrane structure surrounding each muscle fibre. The numbers of muscle fibres per 100 microm(2) was less in crude S-myotrophin-injected normal mice than in PBS-injected mice. Quite similar observations as in the case of normal mice were obtained in the case of ScN mice having heterogeneous gene of dystrophin. In the case of mdx mice, body weight and the weight of M. gluteus major of crude S-myotrophin injected mdx mice was significantly heavier than that of PBS-injected mdx mice. Antibody staining of laminin showed almost intact structure of the basement membrane containing laminin even in skeletal muscle of mdx mice subjected to crude S-myotrophin injection, while irregular and incompletely developed structure of muscle fibres or necrosis were observed in muscle fibres of PBS-injected mdx mice. In spite of crudeness of the preparation, the present animal experiments indicate that S-myotrophin has a strong growth promoting activity of muscle cells of normal and dystrophic mice.
PMID: 16531094 [PubMed - indexed for MEDLINE]

Int J Biochem Cell Biol. 2001 Aug;33(8):831-8.
S-myotrophin promotes the hypertrophy of myotube as insulin-like growth factor-I does.
Hayashi T, Ogawa T, Sato M, Tsuchida N, Fotovati A, Iwamoto H, Ikeuchi Y, Cassens RG, Ito T.
Laboratory of Chemistry and Technology of Animal Products, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
We have reported previously that a novel muscle cell growth factor, having a structure of a peptide with sugar chains, was successfully purified from porcine skeletal muscle. It was named s-myotrophin. To determine the role of s-myotrophin in skeletal muscle growth, the effect of s-myotrophin on primary cultured chick skeletal muscle cells (composed almost totally of multinucleated myotubes) was investigated by comparing s-myotrophin with Insulin-like growth factor-I (IGF-I). Both s-myotrophin and IGF-I significantly increased creatine kinase activity of the cultures; both substances gave similar responses. Intracellar protein content was also increased by the addition of these factors. The content of myosin and actin in s-myotrophin treated culture in the differentiation medium was significantly higher than that of the control (unstimulated). The content of those proteins in IGF-I treated culture was also higher than that of control, but the differences were not statistically significant. Immunoblot analysis confirmed that the amounts of myosin and actin in the myocytes were greatly increased by s-myotrophin stimulation and also by IGF-I stimulation. Morphological observations using an anti-desmin antibody staining procedure demonstrated that the size of both s-myotrophin and IGF-I treated myotubes was appreciably larger than that of control myotubes. These results suggest that s-myotrophin is a potent mediator of skeletal muscle cell hypertrophy thorough the accumulations of muscle structural proteins.
PMID: 11404186 [PubMed - indexed for MEDLINE]

Exp Cell Res. 2010 Nov 1;316(18):3059-66. Epub 2010 Apr 18.
Signalling and the control of skeletal muscle size.
Otto A, Patel K.
School of Biological Sciences, Hopkins Building, University of Reading, Whiteknights Campus, Reading, Berkshire, UK.
Skeletal muscle is highly adaptive to environmental stimuli and can alter its mass accordingly. This tissue is almost unique in that it can increase its size through two distinct mechanisms. It can grow through a cellular process mediated by cell fusion, or it can increase its size simply by increasing its protein content. Understanding how these processes are regulated is crucial for the development of potential therapies against debilitating skeletal muscle wasting diseases. Two key signalling molecules, Insulin like Growth Factor (IGF) and GDF-8/myostatin, have emerged in recent years to be potent regulators of skeletal muscle size. In this review we bring together recent data highlighting the important and novel aspects of both molecules and their signalling pathways, culminating in a discussion of the cellular and tissue phenotypic outcomes of their stimulation or antagonism. We emphasise the complex regulatory mechanisms and discuss the temporal and spatial differences that control their action, understanding of which is crucial to further their use as potential therapeutic targets.
Copyright ? 2010 Elsevier Inc. All rights reserved.
PMID: 20406633 [PubMed - indexed for MEDLINE]

01-16-2011, 03:17 PM
There are so many things we don't know about muscle growth. Good info. Always new discoveries