Elimination kinetic of 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate ester metabolites in calves' urine

J Steroid Biochem Mol Biol. 2008 May;110(1-2):30-8. doi: 10.1016/j.jsbmb.2007.09.024. Epub 2008 Feb 14.


Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C(18) SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCalpha) for steroids were below 0.1 microg L(-1), except for 19-norandrosterone (CCalpha=0.7 microg L(-1)) and estrone (CCalpha=0.3 microg L(-1)). Kinetics of elimination of the administered 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate were established by monitoring 17beta-estradiol, 17alpha-estradiol, estrone and 17beta-nandrolone, 17alpha-nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17alpha-estradiol and 17alpha-nandrolone (>20 and 2 mg L(-1), respectively after 17beta-estradiol 3-benzoate and 17beta-nandrolone laureate administration) whereas 17beta-estradiol, estrone, 17beta-nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the microg L(-1) level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17beta form.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anabolic Agents / administration & dosage
  • Anabolic Agents / pharmacokinetics
  • Anabolic Agents / urine
  • Androstenedione / administration & dosage
  • Androstenedione / analogs & derivatives
  • Androstenedione / pharmacokinetics
  • Androstenedione / urine
  • Animals
  • Cattle
  • Estradiol / administration & dosage
  • Estradiol / analogs & derivatives*
  • Estradiol / pharmacokinetics
  • Estradiol / urine
  • Estranes / administration & dosage
  • Estranes / pharmacokinetics
  • Estranes / urine
  • Estrone / administration & dosage
  • Estrone / pharmacokinetics
  • Estrone / urine
  • Female
  • Kinetics
  • Male
  • Metabolic Clearance Rate
  • Nandrolone / administration & dosage
  • Nandrolone / pharmacokinetics
  • Nandrolone / urine*


  • Anabolic Agents
  • Estranes
  • estradiol 3-benzoate
  • Estrone
  • Androstenedione
  • Estradiol
  • 19-norandrosterone
  • Nandrolone
  • 19-norandrostenedione