Linked Life Data

15459834

Source:http://linkedlifedata.com/resource/pubmed/id/15459834

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2004-10-1
pubmed:abstractText
19-Norandrosterone (19-NA) and 19-noretiocholanolone (19-NE) are the two main urinary indicators used to detect illegal use of nandrolone. Recent studies showed that 19-NA and 19-NE can be endogenously produced in non-treated humans. The concentrations were close to the threshold of the International Olympic Committee (IOC), i.e. 2 ng/ml for men and seem to increase after prolonged intense effort. Androgens are involved in the biosynthesis of estrogens and estrogen has a protective effect against skeletal muscle damage following eccentric exercise. Furthermore, the testicular tissue can synthesize 19-norandrogens from androgens, we hypothetisize that the 19-norandrogen production might be influenced by muscle damage following eccentric exercise. Therefore the purpose of this study is to examine if three different exercise methods will influence the urinary concentration of 19-NA and 19-NE in healthy young subjects. Fifteen amateur hockey players undertook a 30 min submaximal standardized exercise protocol. They were randomised for three different types of exercise, namely a cycle ergometer test (cyclic muscle activity), a treadmill test (concentric muscle activity), or a bench-steptest (eccentric muscle activity) at a target heart rate corresponding to 65 % (+/- 5 %) of Karvonen heart rate. Urine samples were obtained before the test and 60 min and 120 min after the end of exercise. Subjects completed a Likert scale of muscle soreness before and 12 h after exercise. 19-NA and 19-NE were determined by gas chromatography-tandem mass spectrometry (GC-MS-MS). Baseline urinary 19-NA and 19-NE concentrations were under limit of detection of 0.05 ng/ml, except for one sample (0.13 ng/ml). No 19-NA or 19-NE could be detected post exercise. In our experimental conditions, the exercise mode (eccentric or concentric) had no impact on 19-NA or 19-NE excretion. Our findings confirm that the current International Olympic Committee threshold level for nandrolone metabolites is sufficiently high to avoid false positive cases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0172-4622
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
528-32
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Norandrosterone and noretiocholanolone concentration before and after submaximal standardized exercise.
pubmed:affiliation
Vrije Universiteit Brussel, Fac LK, Menselijke Fysiologie en Sportgeneeskunde, 1050 Brussel, Belgium.
pubmed:publicationType
Journal Article, Clinical Trial, Randomized Controlled Trial