title: Atypical excretion profile and GC/C/IRMS findings may last for nine months after a single dose of nandrolone decanoate.
abstract: The use of the anabolic androgenic steroid nandrolone and its prohormones is prohibited in sport. A common route of nandrolone administration is intramuscular injections of a nandrolone ester. Here we have investigated the detection time of nandrolone and 19-norandrosterone and 19-noretiocholanolone metabolites in eleven healthy men after the administration of a 150 mg dose of nandrolone decanoate. The urinary concentrations of nandrolone and the metabolites were monitored by GC-MS/MS for nine months and in some samples the presence of 19-norandrosterone was confirmed by GC/C/IRMS analysis. The participants were genotyped for polymorphisms in PDE7B1 and UGT2B15 genes previously shown to influence the activation and inactivation of nandrolone decanoate. There were large inter-individual variations in the excretion rate of nandrolone and the metabolites, although not related to genetic variations in the UGT2B15 (rs1902023) and PDE7B1 (rs7774640) genes. After the administration, 19-norandrosterone was found at 2-8-fold higher concentrations than 19-noretiocholanolone. We showed that nandrolone doping can be identified 4 and 9 months after the injection of only one single dose in six and three individuals, respectively. We also noted that GC/C/IRMS confirms the presence of exogenous 19-norandrosterone in the urine samples, showing δ13 values around -32 ‰. This was true even in a sample that was not identified as an atypical finding after the GC-MS/MS analysis further showing the power of using GC/C/IRMS in routine anti-doping settings.
authors: Doping Control Laboratory, Division of Clinical Pharmacology, Karolinska University Hospital, SE-141 86 Stockholm, Sweden; Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-14186 Stockholm, Sweden.
authors: Elzbieta
authors: E
authors: Palonek
authors: Doping Control Laboratory, Division of Clinical Pharmacology, Karolinska University Hospital, SE-141 86 Stockholm, Sweden; Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-14186 Stockholm, Sweden.
authors: Magnus
authors: M
authors: Ericsson
authors: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-14186 Stockholm, Sweden.
authors: Nina
authors: N
authors: Gårevik
authors: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-14186 Stockholm, Sweden.
authors: Anders
authors: A
authors: Rane
authors: Department of Medicine/Huddinge, Karolinska Institutet and Centre for Andrology and Sexual Medicine, Karolinska University Hospital C2:84, SE 141 86 Stockholm, Sweden.
authors: Mikael
authors: M
authors: Lehtihet
authors: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-14186 Stockholm, Sweden. Electronic address: lena.ekstrom@ki.se.
authors: Lena
authors: L
authors: Ekström
mesh_terms: D000328:Adult; D008401:Gas Chromatography-Mass Spectrometry; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009277:Nandrolone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics / Q000652:urine; D000077603:Nandrolone Decanoate
chemical_list: D009277:Nandrolone; D000077603:Nandrolone Decanoate
keywords: 19-Norandrosterone; 19-Noretiocholanolone; Anabolic steroids; GC/C/IRMS; Nandrolone; UGT2B15