Epitestosterone is an endogenous steroid , an inactive epimer of the male sex hormone testosterone . It differs from the latter only in spatial isomerism at the 17th carbon atom (see numbering scheme ).
In boys, the level of epitestosterone prevails over the level of testosterone before the onset of puberty , then it quickly reaches a value of approximately 1: 1. [one]
Content
- 1 History
- 2 Sports
- 3 Recommended reading
- 4 notes
History
Epitestosterone was first obtained in 1947 from sections of rabbit liver. [2]
Sport
In professional sports, athletes are tested for the ratio of testosterone / epitestosterone. It is known that in young men it is usually equal to 1, although the statistical distribution has an additional maximum in the range of 0.1-0.2 ratios, which is typical for Asian athletes. In 1983, the IOC decided that if a value of 6: 1 is exceeded, an athlete may be punished for doping . The World Anti-Doping Agency reduced this value to 4: 1 in 2005. [3] Accumulated data on possible individual variations of this ratio associated with gene variations, such as UGT2B17 . In this regard, an athlete with abnormal T / E indicators may be subjected to additional testing. Also, if the permissible concentration of epitestosterone in the urine is exceeded above 200 ng / ml, the athlete's test can be declared positive.
Recommended
- 2003 review: Stárka L. Epitestosterone (Eng.) // J. Steroid Biochem. Mol. Biol. : journal. - 2003 .-- October ( vol. 87 , no. 1 ). - P. 27—34 . - PMID 14630088 .
Testosterone http://athletics.in.ua/Stati/Pitanie-i-farmakologiya/testosteron.html (unavailable link)
Notes
- ↑ Lapcík O., Hampl R., Hill M., Stárka L. Plasma levels of epitestosterone from prepuberty to adult life (Eng.) // J. Steroid Biochem. Mol. Biol. : journal. - 1995. - December ( vol. 55 , no. 3-4 ). - P. 405-408 . - PMID 8541237 .
- ↑ Clark LC, Kochakian CD. The in vitro metabolism of testosterone to 4-androstenedione-3.17 cis-testosterone and other steroids by rabbit liver slices. Journal of biological chemistry. 1947; 170: 22–23.
- ↑ Bowers LD Testosterone doping: dealing with genetic differences in metabolism and excretion // J. Clin. Endocrinol. Metab. : journal. - 2008 .-- July ( vol. 93 , no. 7 ). - P. 2469-2471 . - DOI : 10.1210 / jc.2008-0977 . - PMID 18617700 .