these two paragraphs in particular have some neat things.
first one....is that igf-1 has no anabolic effects unless it gets into the muscle. simply injecting igf-1 will not yeil anything, and doesnt increase igf-1 levels in the muscle. there is a way to increase igf-1 expression the muscle, but its not going to be available to bodybuilders for a while - its injecting a certain kind of vrius.
second one illustarets why t3 is anabolic. increases gh and igf-1(igf-1 in the muscle through the igf-1 receptor).
http://mesomorphosis.com/articles/haycock/growth-factors-03.htmGetting IGF-1 inside the muscle as apposed to in the blood has shown to be extremely anabolic in another exciting animal study using viral mediated gene therapy (12). In this study, a recombinant adeno-associated virus, directing overexpression of insulin-like growth factor I (IGF-I) in mature muscle fibers, was injected into the muscles of mice. The DNA that was originally in the virus was removed along with markers that stimulate immune response. DNA coding for IGF-1 was then put into the virus along with a promoter gene to ensure high rates of transcription. The results were dramatic causing a 15% increase in muscle mass and a 14% increase in strength in young adult mice, once again, without additional exercise. Obviously this technology is not going to be available to bodybuilders any time soon, nevertheless, it’s exciting to consider the possibilities.
Thyroid hormones, on the other hand, offer significant benefits when used cautiously and "properly". They should not be used haphazardly as a fat loss agent however, instead they are valuable in correcting thyroid dysfunction brought on by androgen use. When done properly, T3 is used as "replacement therapy" and serves only to normalize decreased T3 levels. Research has shown that high dose androgens pushes T3 levels down (14,15). This is significant because the real value of optimal thyroid levels is not for fat loss, but instead for optimum anabolic activity. T3 has diverse facilitative anabolic effects including, increasing GH secretion(16,17), up-regulating GH receptors (18), up-regulating IGF-1 receptors (19,20), and other less well defined anabolic effects (21,22). Don’t get the wrong idea however, for T3 to facilitate anabolism, it must stay in the high normal range. A little too high or a little too low significantly changes the biological effects of thyroid hormones. Bringing T3 levels too high will undoubtedly backfire and lead to muscle, strength losses, and rebound fat gain.
