Influence of delivery mode on the urinary excretion of nandrolone metabolites.
BACKGROUND
This study examined the influence of a supplement matrix on the excretion pattern of nandrolone metabolites in response to ingestion of a trace amount of 19-norandrostenedione.


METHODS
Ten male and nine female volunteers (mean ± SD: age = 26 ± 3 yr, height = 1.71 ± 0.09 m, body mass = 70.9 ± 13.2 kg) were recruited. On two occasions, subjects entered the laboratory in the morning after an overnight fast. After an initial urine collection, subjects ingested either 500 mL of plain water or a commercially available energy bar; 10 µg of 19-norandrostenedione was added to each. The volume of each urine sample passed during the next 24 h was measured, and an aliquot was retained for analysis. All samples were analyzed for the metabolites 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE) by gas chromatography-mass spectrometry.


RESULTS
The total volume of urine passed was higher in the water trial (2.10 ± 0.52 L) than in the bar trial (1.85 ± 0.55 L; P = 0.040). Baseline urinary 19-NA concentrations were all below the limit of quantification for the assay. Peak urinary 19-NA was lower (P = 0.002) in the water trial (4.80 ± 2.84 ng·mL(-1)) than in the bar trial (8.46 ± 4.44 ng·mL(-1)). The time elapsed between ingestion of the supplement and the peak urinary 19-NA concentration was longer (P = 0.023) on the bar trial (4.6 ± 2.4 h) than on the water trial (2.8 ± 1.9 h). There was no difference in the total recovery of 19-NA + 19-NE between the liquid and solid supplements (water 30 ± 10%; bar 28 ± 12%; P < 0.140).


CONCLUSIONS
Peak 19-NA concentrations were higher, and occurred later, when the 19-norandrostenedione was added to a solid supplement. This may be due to a slower rate of absorption and/or a reduced diuresis, resulting in a longer period for the metabolites to accumulate in the urine.
Watson
Phillip
P
School of Sport and Exercise Sciences, Loughborough University, Loughborough, United Kingdom.
Houghton
Ed
E
Grace
Philip B
PB
Judkins
Catherine
C
Dunster
Paula M
PM
Maughan
Ronald J
RJ
D000327:Adsorption; D000328:Adult; D045930:Anabolic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000735:Androstenedione / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D019587:Dietary Supplements; D004300:Doping in Sports; D004326:Drinking; D004435:Eating; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D009277:Nandrolone / Q000652:urine*; D055815:Young Adult
D045930:Anabolic Agents; D000735:Androstenedione; D009277:Nandrolone; C002828:19-norandrostenedione