Update on nandrolone and norsteroids: how endogenous or xenobiotic are these substances?

  title={Update on nandrolone and norsteroids: how endogenous or xenobiotic are these substances?},
  author={V{\'e}ronique-Aur{\'e}lie Bricout and Françoise Wright},
  journal={European Journal of Applied Physiology},
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… 

x vivo spontaneous generation of 19-norandrostenedione and nandrolone etected in equine plasma and urine

It is concluded that all NAED and nandrolone detected in stored plasma samples of stallions and most of them in the stored urine samples are not from endogenous origins but spontaneously generated during sample storage, most likely from spontaneous decarboxylation of androstenedione- 19-oic acid and testosterone-19-Oic acid.

Nandrolone: a multi-faceted doping agent.

A set of strict identification criteria is applied to judge correctly an analytical finding of nandrolone metabolites, and the possible influence of interfering drugs, urine storage or natural production is taken into account by applying appropriate rules and regulations.

Determination of the origin of urinary norandrosterone traces by gas chromatography combustion isotope ratio mass spectrometry.

The origin of NA in doping control samples was determined as either endogenous or exogenous, which is less depleted in (13)C due to a dietary mixture of C(3)- and C(4)-plants.

Modulation of phase II metabolism : A case study on 19-norandrosterone

  • Biology, Medicine
  • 2014
Among the compounds tested, ibuprofen, ketoconazole and miconazole were the most potent inhibitors of the 19-norandrosterone glucuronide formation by either pooled human liver microsomes or UGT2B7 and UGT 2B17 isoenzymes.

In vitro evaluation of the effects of anti-fungals, benzodiazepines and non-steroidal anti-inflammatory drugs on the glucuronidation of 19-norandrosterone: implications on doping control analysis.

We have studied whether the phase II metabolism of 19-norandrosterone, the most representative metabolite of 19-nortestosterone (nandrolone), can be altered in the presence of other drugs that are



Urinary nandrolone metabolites of endogenous origin in man: a confirmation by output regulation under human chorionic gonadotropin stimulation.

In conclusion, insulinic stress did not significantly alter nandrolone metabolism, whereas the effect of hCG was a stimulation of NA excretion in all subjects, which constitutes strong support for the endogenous origin of low basalNA excretion.

Evidence for the presence of endogenous 19-norandrosterone in human urine.

Pharmacokinetics of 19-nortestosterone esters in normal men.

Urinary excretion of 19-norandrosterone of endogenous origin in man: quantitative analysis by gas chromatography-mass spectrometry.

Urinary metabolites of administered 19-nortestosterone.

The reported high anabolic (myotrophic) and low androgenic activity of 19-nortestosterone and its esters in rodents (l-5) prompted an oxperiment to determine whether this substance was useful in

Issues in detecting abuse of xenobiotic anabolic steroids and testosterone by analysis of athletes' urine.

Among ancillary tests to help discriminate between naturally increased T/E values and those reflecting T use, the most promising is determination of the carbon isotope ratio.

Nandrolone excretion is not increased by exhaustive exercise in trained athletes.

This study provides compelling evidence that endogenous nandrolone production in male athletes, during two very different types of exercise, produces urine levels far below the IOC threshold of 2 ng.mL(-1) urine, and thus exercise does not induce endogenous n androlone secretion.

Metabolism of 19-nortestosterone by human prostate.

Metabolism and receptor binding of nandrolone and testosterone under in vitro and in vivo conditions.

Both in vitro and in vivo studies show that nandrolone and T were relatively stable in spleen, thymus and muscular tissue and, as a result, the same amount of N and T was bound to the receptor in these tissues in the in vivo infusion experiment.