%0 Journal Article
%T Effects of eight weeks of an alleged aromatase inhibiting nutritional supplement 6-OXO (androst-4-ene-3,6,17-trione) on serum hormone profiles and clinical safety markers in resistance-trained, eugonadal males
%A Dan Rohle
%A Colin Wilborn
%A Lem Taylor
%A Chris Mulligan
%A Richard Kreider
%A Darryn Willoughby
%J Journal of the International Society of Sports Nutrition
%D 2007
%I BioMed Central
%R 10.1186/1550-2783-4-13
%X Athletes have long been looking for a way to gain an edge in competition, which has lead many to turn to anabolic steroids. Anabolic steroids are defined as testosterone (TST) or derivatives of TST that are used for their ability to create a state of nitrogen retention and increase fat-free mass by stimulating protein synthesis and/or by decreasing protein breakdown. It has been previously thought that anabolic steroids did not cause an increase in muscle size and strength, but now more recent studies have shown the effect that supra-physiological levels of TST and TST derivatives can increase muscle size and strength in males [1-7].Once produced, TST does not circulate freely in the blood. Rather, total testosterone (TT) is almost 100% bound in blood to proteins with 40% bound to albumin, 40% bound to a ¦Â-globulin called sex hormone binding globulin (SHBG), and 17% is bound to other proteins. The small fraction of TST that is not bound is considered the free testosterone (FT) and is the bioactive component of the hormone. Once bound to its androgen receptor, TST can also be converted to dihydrotestosterone (DHT) by the enzyme 5-¦Á reductase. Alternatively, TST can be converted into estradiol through aromatization by the action of the enzyme aromatase.There are pro-hormone nutritional supplements available, such as androstenedione, that are precursors to TST, and designer androstenedione derivatives such as androstenediol that are purported to support TST production. These compounds are alleged to increase TST, or to increase the concentration of compounds that can act like TST. There are data in young men demonstrating that the acute sublingual ingestion of androstenedione and androstenediol increased FT and TT up to 180 min [8] and 240 min [9] after ingestion. However, these are acute studies with a small window of TST elevation and do not relevantly reflect the manner in which these types of supplements are typically utilized. More appropriately, there are studies
%U http://www.jissn.com/content/4/1/13