Endogenic nortestosterone in cattle?

Brabander, H.F. De; Hende, J. Van; Batjoens, Peter; Hendriks, Lutgart; Raus, Jef; Smets, Felix; Pottie, G.; Ginkel, Leen van; Stephany, R. W.

doi:10.1039/an9941902581

Cited by 50 publications

(45 citation statements)

References 2 publications

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“…6,7 There is added impetus to establish the nature of major metabolites in target samples given the recent EU Directive 1 requiring increased on-farm sampling, and reports that there may be endogenous sources of 19NT. [7][8][9][10][11] In this study, radiotracer, chromatographic and mass spectrometric procedures were used to investigate the disposition and biotransformation of 19NT laurate (19NTL) in cattle, with the aim of establishing appropriate target residues and tissues for surveillance of 19NT use. solved in dichloromethane (80 ml).…”

Section: Introductionmentioning

confidence: 99%

Residues and metabolism of 19-nortestosterone laurate in steers†

Sauer¹,

Howells²,

Bellworthy³

et al. 1998

Analyst

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The illegal use of nandrolone) and its esters in livestock, for growth promotion purposes, has been widely reported in the European Union. The target residues for surveillance of abuse in bovine urine and bile samples are 17a-and 17b-19NT, although this choice of target residues is not based on in vivo radiotracer biotransformation data. In this study, four steers were administered [ 3 H 2 ]-and [ 2 H 3 ] 17b-19NT laurate (2 mg kg 21 body mass) by intramuscular injection and blood, urine, faeces and bile samples were taken for 30 d until slaughter, after which tissues were sampled for total residue analysis. Total plasma radiolabelled residues reached a maximum of 56.3 ± 15.9 pmol ml 21 at 36 h and were still appreciable (13.3 ± 1.6 pmol ml 21 ) 30 d after treatment. Throughout the study period, total residue concentrations in bile (about 2-16 nmol ml 21 ), urine and faeces (0.5-3 nmol ml 21 or g 21 ) were higher than in other tissues sampled at slaughter. At slaughter there was evidence of residue accumulation in pigmented eye tissue (33.1 ± 6.1 pmol g 21 ) and in white (13.4 ± 3.4 pmol g 21 ) and black hair (28.9 ± 8.9 pmol g 21 ). Evaluation of radio-HPLC profiles of urine and bile extracts generally indicated that 19NT and 19NT laurate residues were present in relatively small amounts among a complex mixture of metabolites. GC-MS analysis of glucuronidase-hydrolysed bile extracts indicated that the major metabolites were 5b-estrane-3a,17a-diol, 5a-estrane-3b,17a-diol, 5a-estran-3a-ol-17-one (norandrosterone) and estra-1,3,5(10)-triene-3,17a-diol (17a-estradiol).

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Section: Introductionmentioning

confidence: 99%

Residues and metabolism of 19-nortestosterone laurate in steers†

Sauer¹,

Howells²,

Bellworthy³

et al. 1998

Analyst

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“…The androgen boldenone can be synthesized de novo in cattle feces by microbial activity [19][20][21]. Nandrolone has been detected in the urine of pregnant cows in their last trimester of pregnancy [22,23] and their calves for up to 7 d after birth [23]. The synthetic progestogens melengestrol and melengestrol acetate were included because they are supplemented into animal feed for growth promotion and synchronization of estrous [11].…”

Section: Methodsmentioning

confidence: 99%

Stability, preservation, and quantification of hormones and estrogenic and androgenic activities in surface water runoff

Havens

Hedman

Hemming³

et al. 2010

Enviro Toxic and Chemistry

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Degradation of hormones that may occur during storage of surface water samples can lead to underestimations in estrogenic and androgenic activities and inaccuracies in hormone concentrations. The current study investigated the use of sodium azide, hydrochloric acid (HCl), and sulfuric acid (H₂SO₄) to inhibit the degradation of hormones and estrogenic and androgenic activities in samples of surface water runoff from cattle manure-amended fields during storage at 4°C. Hormones and hormone metabolites were extracted using solid-phase extraction and analyzed using high-performance liquid chromatography (HPLC) with tandem MS. Estrogenic and androgenic activities were assessed by E-screen and A-screen, respectively. Results of the current study indicate significant degradation of estrogenic, androgenic, and progestogenic hormones and activities, which is likely attributable to microbial activity, within hours of sample collection. The inclusion of internal standards provides a means to account for hormone losses caused by extraction inefficiency and to some extent degradation. However, internal standards are unable to adequately account for significant losses and are not available for E-screen and A-screen. Sodium azide did not adequately inhibit androgen degradation at the concentration used (1 g/L). Acid preservation (HCl or H₂SO₄, pH 2) stabilized the estrogenic and androgenic activities, and coupling acid preservation with the use of internal standards resulted in reliable and accurate recovery of a suite of androgens, estrogens, and progestogens for up to 14 d of storage at 4°C.

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“…[7][8][9][10][11][12][13] In bovines, 17aN, ABA and NorE have also been detected as main metabolites in cows and calves. [14][15][16][17][18] 17bN, isomers of 3-hydroxyestran-17-one (NorA, NorE, NorEpiA) and isomers of estrane-3,17-diol (BAB and ABB) have been identified in miniature pigs after the administration of 17bN laurate. 19,20 In recent years, different authors have reported the endogenous production of 17bN or its metabolites in different species.…”

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confidence: 99%

Detection of the administration of 17β‐nortestosterone in boars by gas chromatography/mass spectrometry

Ventura

Roig

Pérez

et al. 2008

Rapid Comm Mass Spectrometry

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17beta-Nortestosterone (17betaN) is illegally used in livestock as a growth promoter and its endogenous production has been described in some animals, such as adult boars. In this paper, the metabolism of 17betaN in boars has been studied by gas chromatography/mass spectrometry (GC/MS) in order to identify markers of the exogenous administration. Administration studies of intramuscular 17betaN laurate to male pigs were performed. Free, sulphate and glucuronide fractions of the urine samples were separated and the steroids present were quantified by GC/MS. 17betaN was detected in some pre-administration samples. After administration, 17betaN, norandrosterone, noretiocholanolone (NorE), norepiandrosterone, 5beta-estrane-3alpha,17beta-diol and 5alpha-estrane-3beta,17beta-diol were detected in different fractions, being the most important metabolites, 17betaN excreted as a sulphate and free NorE. Samples collected in routine controls were also analyzed by GC/MS to identify endogenous compounds. 17betaN, norandrostenedione and estrone were detected in almost all the samples. No other 17betaN metabolites were detected. According to these results, the detection by GC/MS of some of the 17betaN metabolites described above, different from 17betaN, could be indicative of the exogenous administration of 17betaN to boars.

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Endogenic nortestosterone in cattle?

Cited by 50 publications

References 2 publications

Residues and metabolism of 19-nortestosterone laurate in steers†

Residues and metabolism of 19-nortestosterone laurate in steers†

Stability, preservation, and quantification of hormones and estrogenic and androgenic activities in surface water runoff

Detection of the administration of 17β‐nortestosterone in boars by gas chromatography/mass spectrometry

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