How much ? I know it's been said many times that its actions are not AR mediated but through other mechanisms.
I found an interesting study which contradicts this . Take a look :
J Steroid Biochem Mol Biol. 2005 Apr;94(5):481-7. Epub 2005 Mar 17.
Anabolic-androgenic steroid interaction with rat androgen receptor in vivo and in vitro: a comparative study.
Feldkoren BI, Andersson S.
Department of Obstetrics-Gynecology and Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9032, USA.
Abstract
Anabolic steroids are synthetic derivatives of testosterone and are characterized by their ability to cause nitrogen retention and positive protein metabolism, thereby leading to increased protein synthesis and muscle mass. There are disagreements in the literature in regards to the interaction of anabolic steroids with the androgen receptor (AR) as revealed by competitive ligand binding assays in vitro using cytosolic preparations from prostate and skeletal muscle. By use of tissue extracts, it has been shown that some anabolic steroids have binding affinities for the AR that are higher than that of the natural androgen testosterone, while others such as stanozolol and methanedienone have significantly lower affinities as compared with testosterone. In this study we show that stanozolol and methanedienone are low affinity ligands of the rat recombinant AR as revealed by a ligand binding assay in vitro, however, based on a cell-based AR-dependent transactivation assay, they are potent activators of the AR. We also show that a single injection of stanozolol and methanedienone causes a rapid cytosolic depletion of AR in rat skeletal muscle.
Based on these results, we conclude that anabolic steroids with low affinity to AR in vitro, can in fact in vivo act on the AR to cause biological responses.
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Another one that completely contradicts the theory because when administered with an
androgen receptor antagonist, dianabol's anabolic activity was vastly
reduced :
springerlink.com/content/u636851135p55013
"...The results obtained upon joint administration of dianabol and the
antagonist were somewhat unexpected. The latter in doses of 2.5 and
7.5mg/rat/day caused a decrease in the response to dianabol only on the
part of the muscle and inhibited the stimulatory effect of dianabol on
the mass of the accessory (androgen sensitive) organs only in the
maximum dose...."
Can we put an end to dbol's debated on its androgenic activity ?
Please share your opinions.