Study of the metabolism of testosterone, nandrolone and estradiol in cattle†

Abstract

The current metabolism study was undertaken to identify key analytes in urine, plasma and bile following testosterone, nandrolone and estradiol administrations to cull cows, heifers and steers. This information will be used to develop confirmatory analysis procedures. In the present study, mixtures (1:1) of testosterone, nandrolone or estradiol and their deuterium labelled analogues were administered to cull cows, heifers and steers. Two analogues of deuterium labelled testosterone were synthesised and administered, to facilitate identification of metabolites. Following administration, urine, plasma and bile samples were collected and subjected to solid phase extraction. The extracts were derivatised and analysed by GC-MS. The major analytes derived from the administered steroids were identified on the basis of the twin ion peaks produced for their non-labelled and deuterium labelled analogues and their stereochemistries determined by comparison of retention times with appropriate reference standards. Using suitable internal markers, excretion profiles for the major analytes in urine and plasma have been determined and levels in isolated bile samples estimated. This work is on-going, and this paper is a summary of some of the studies completed to date.

A recombinant Fab fragment-based electrochemical immunosensor for the determination of testosterone in bovine urine

“…4-Androsten-3,17-diol, etiocholanolone and epietiocholanolone are considered to be main metabolites of testosterone in bovine urine following administration (Samuels et al, 1998). Other possible major metabolites are 2␣-hydroxytestosterone, 6␤-hydroxytestosterone, 16␣-hydroxytestosterone, 16␤-hydroxytestosterone and estradiol (Venturelli et al, 1995;Li et al, 2002;Sanwald et al, 1995).…”

“…There are various analytical methods used for the detection of testosterone in biological fluids including, HPLC (Li et al, 2002;Navajas et al, 1995), GC-MS (Samuels et al, 1998;Saudan et al, 2004) and LC-MS offers a simplified, specific and sensitive alternative to GC-MS (Leinonen et al, 2004). Whilst these techniques have been used as quantitative and confirmatory methods, they do need expensive instrumentation, specialized personnel * Corresponding author.…”

Report for 2011 on the results from the monitoring of veterinary medicinal product residues and other substances in live animals and animal products

“…The non-compliant samples were found in bovines (n = 39; 0.13 %), pigs (n = 6; 0.06 %), poultry (n = 6; 0.13 %) and aquaculture (n = 2; 0.57 %). For 26 results of anabolic steroids (80 %), Member States indicated that the source was most likely the endogenous production as reported in previous studies (Clouet et al, 1997;Samuels et al, 1998). No evidence of illegal use was found for other 5 non-compliant results for anabolic steroids.…”

Report for 2013 on the results from the monitoring of veterinary medicinal product residues and other substances in live animals and animal products

“…The non-compliant samples were found in bovines (n = 9; 0.04 %), pigs (n = 19; 0.18 %), sheep and goats (n = 4; 0.35 %) and horses (n = 3; 1.73 %). Some Member States indicated that residue findings on steroid hormones may not be attributable to illegal treatment, as the source was most likely the endogenous production as reported in previous studies (Clouet et al, 1997;Samuels et al, 1998).…”