| Title |
Update on nandrolone and norsteroids: how endogenous or xenobiotic are these substances?
|
|---|---|
| Published in |
European Journal of Applied Physiology, March 2004
|
| DOI | 10.1007/s00421-004-1051-3 |
| Pubmed ID | |
| Authors |
V. Bricout, F. Wright |
| Abstract |
Norsteroids are xenobiotics with androgenic and anabolic properties known since as far back as the 1930s. In doping controls, the use of the banned xenobiotic norsteroids is detected in the competitor's urines by the measurement of norandrosterone (19-NA) and noretiocholanolone (19-NE), which are the main metabolites for nandrolone (NT) and most norsteroids with anabolic properties. In 1996, the IOC subcommission "Doping and Biochemistry of Sport" informed the Heads of the "IOC Accredited Laboratories" that the recommended cut-off limit for reporting an offence was to be 1-2 ng ml(-1) urine for either 19-NA or 19-NE. We will discuss how technical progress in gas chromatography coupled to high-resolution mass spectrometry permitted a dramatic increase in sensitivity with a detection limit of 1 pg ml(-1) urine, or less, and an assay limit of 20-50 pg ml(-1) urine, for either 19-NA or 19-NE. As a paradox, norsteroids have been known for decades as not only xenobiotics but also obligatory endogenous intermediates in the biosynthesis of estrogens from androgens in all species, man included. It is this biochemical observation which fed the active scientific and medical controversy initiated in 1998 over the possibly endogenous production of nandrolone and metabolites well over the new IOC's recommended cut-off limit of 2 ng ml(-1) urine. Notwithstanding the particular technical difficulties attached, we will provide data and discuss the minute endogenous levels detected and measured in man either at rest, after performance or training and compare them to the relatively high levels reported in male athlete's doping controls today. We will also discuss data on the pharmacological effects of some contraceptive therapies containing norsteroids in women. In view of the well-documented noxious effects repeatedly observed after anabolic steroid misuse, the confirmation and implementation of technically proven procedures for reporting norsteroid abuse in sports seems an important enough goal to protect athlete's health against such abuses and justifies up dating the review of the patent scientific and medical experience and knowledge gained over the last 50 years on nandrolone and its minor production in man and woman. |
Mendeley readers
The data shown below were compiled from readership statistics for 40 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United Kingdom | 1 | 3% |
| Portugal | 1 | 3% |
| Unknown | 38 | 95% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 7 | 18% |
| Student > Master | 6 | 15% |
| Student > Doctoral Student | 4 | 10% |
| Student > Bachelor | 4 | 10% |
| Student > Ph. D. Student | 4 | 10% |
| Other | 5 | 13% |
| Unknown | 10 | 25% |
| Readers by discipline | Count | As % |
|---|---|---|
| Agricultural and Biological Sciences | 6 | 15% |
| Sports and Recreations | 4 | 10% |
| Biochemistry, Genetics and Molecular Biology | 3 | 8% |
| Chemistry | 3 | 8% |
| Psychology | 3 | 8% |
| Other | 5 | 13% |
| Unknown | 16 | 40% |
Attention Score in Context
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 28 August 2019.
All research outputs
#8,535,472
of 25,374,647 outputs
Outputs from European Journal of Applied Physiology
#2,159
of 4,345 outputs
Outputs of similar age
#21,960
of 64,907 outputs
Outputs of similar age from European Journal of Applied Physiology
#6
of 18 outputs
Altmetric has tracked 25,374,647 research outputs across all sources so far. This one is in the 43rd percentile – i.e., 43% of other outputs scored the same or lower than it.
So far Altmetric has tracked 4,345 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 14.6. This one is in the 39th percentile – i.e., 39% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 64,907 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 11th percentile – i.e., 11% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 18 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 61% of its contemporaries.