So many products claim to increase androgenic hormones. How do these testosterone precursors and steroids work? Surely you've come across and heard a lot of different info on this.
Unfortunately, there are many misconceptions about how androgens make muscles grow. With all this BS around, it's important to have some information on how steroids really work. Here's an update on the latest scientific findings.
To gain a working knowledge of androgen action, we need to travel to the cellular level. Imagine a steroid molecule as a key floating through the bloodstream. This key fits into a lock (a receptor) and, once the hormone is bound to a cell in this way, all sorts of activity goes on in the cell. One of these cellular events is protein synthesis.
Receptors are located all over the body, but the ones we're concerned with are in muscle. Muscle serves as a primary target tissue for androgens circulating in the bloodstream.
Believe it or not, when athletes first started using androgens, most scientists did not believe they worked. In fact, understanding how steroids induce anabolism in muscle has been one of the great mysteries of science, until recently. The androgen receptor (AR) in human muscle was located in 1981, when a group of Swedish and Polish scientists identified its presence in the quadriceps.
Data shows that, at normal physiological levels, the ARs are completely saturated. With all the receptors supposedly filled, scientists mistakenly thought that additional steroids introduced into the system would be unable to effect changes on muscle growth. (Were they wrong!) Also adding to the argument that steroids had no influence on muscle size was the belief that the AR down-regulates (stops working) after a guy goes through puberty. Therefore, it followed that there were no ARs upon which the androgens could act. But the latest studies on 'roids show that they can work outside of the receptor complex.
Studies have also shown that certain steroids have what is called a high binding affinity. Greater binding increases the possibility that the steroid will be able to exert its effects on muscle. One study found that 19-nortestosterone derivatives (trade names Deca-Durabolin and Laurabolin), methenolone (Primobolan) and testosterone all have a high binding affinity.
What's surprising is that some of the more popular steroids among athletes have a low binding affinity for the AR. Those showing low binding ability are stanozolol (Winstrol), methandrostenolone (Dianabol, Reforvit-B) and fluoxymesterone (Halotestin, Stenox). Interestingly, though these steroids don't bind to the AR very well, they are some of the most effective drugs for muscle building. That means some steroids might be using other pathways to exert their effects on protein synthesis, namely, the insulinlike growth factor-1 (IGF-1) system. Also, how big a role binding affinity plays in humans using large dosages should be further examined.