Epitestosterone
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| Image:Epitestosterone.png | |
| Epitestosterone
| |
| Systematic (IUPAC) name | |
| 17-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17- dodecahydrocyclopenta[a]phenanthren-3-one | |
| Identifiers | |
| CAS number | |
| ATC code | ? |
| PubChem | ? |
| Chemical data | |
| Formula | C19H28O2 |
| Mol. mass | 288.42 |
| Pharmacokinetic data | |
| Bioavailability | ? |
| Metabolism | ? |
| Half life | ? |
| Excretion | ? |
| Therapeutic considerations | |
| Pregnancy cat. |
? |
| Legal status | |
| Routes | ? |
Epitestosterone is a natural steroid, an inactive epimer of the hormone testosterone. Structurally, it differs from testosterone only in the configuration at the OH-bearing carbon, C17. Epitestosterone is believed to form in a similar way to testosterone; a 1993 study found that around 50% of epitestosterone production in human males can be ascribed to the testis,[1] although the exact pathway of its formation is still the subject of research. It has been shown to accumulate in mammary cyst fluid and in the prostate.[1] Epitestosterone levels are typically highest in young males; however, by adulthood, most healthy males exhibit a testosterone to epitestosterone ratio (T/E ratio) of about 1:1.[1]
Epitestosterone and testosterone
It has been shown that exogenous administration of testosterone does not affect levels of epitestosterone in the body. As a result, tests to determine the ratio of testosterone to epitestosterone in urine are used to find athletes who are doping.[1] Most persons have a ratio of about 1:1 testosterone to epitestosterone (T/E ratio) in their urine. However, it is not uncommon to find T/E ratios of up to 4:1 and even T/E ratios of 10:1 can be normal for some individuals. T/E tests are most common because a person may naturally have high levels of testosterone, but even so T/E ratios tend to stay close to 1:1.
Epitestosterone has not been shown to enhance athletic performance, although administration of epistestosterone can be used to mask a high level of testosterone if the standard T/E ratio test is used. As such, epitestosterone is banned by many sporting authorities as a masking agent for testosterone.
In 1996 the US athlete Mary Decker failed a T/E test with a T/E ratio of greater than 6, the limit in force at the time. She took the case to arbitration, arguing that birth control pills can cause false positives for the test, but the arbitration panel ruled against her.
On September 20, 2007 Floyd Landis was stripped of his title as winner of the Tour de France, and was subjected to a two year ban from professional racing after a second test showing an elevated T/E ratio. Test results from Floyd Landis' "A" test sample indicated that while the ratio was 11:1, his testosterone level was in the normal range and the problem was actually a deficient level of epitestosterone. Landis won the 17th stage of the tour; however, tests taken immediately after the stage victory showed a T/E ratio of 11:1[1], more than double the 4:1 imposed limit (recently lowered from prior limits of 8:1 and 6:1). Landis had emphatically denied the charge, pointing out the scientific data that testosterone cannot enhance athletic performance unless taken over an extended period of time with regular doses.
External links
- Landis has T/E ratio twice the tour limit
- Institute of Endocrinology Abstract on Epistestosterone
- Sex, drugs and sports: Prostaglandins, epitestosterone and sexual development
- Endocrine Functions in Male and Female Homosexuals
- Homosexual women: an endocrine and psychological study.
Notes
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
