Radioimmunoassays for free and conjugated trienbolone and for trienbolone acetate in bovine tissue and plasma samples

Enzyme-linked immunosorbent assay-based detection of free trenbolone in bovine bile

A rapid antibody-based detection system has been developed for the presence of free trenbolone in bovine samples. Polyclonal antibodies were produced that showed specificity toward epitopes located around the steroidal A-ring of the trenbolone molecule. These antibodies were shown to have little or no recognition for many closely related compounds. The antibodies were utilized as the specific biorecognition molecules in competitive and inhibitive enzyme-linked immunosorbent assay systems. While both assays were able to detect low nanogram concentrations of trenbolone in bovine bile, the competitive format was more sensitive (2.41 vs 17.15 ng/mL for TRAb2 and 3.31 vs 30.73 ng/mL for TRAb1). This format was also more accurate and the data produced by this assay fitted more closely to the four parameter equation used to calculate the standard curve. This was a common finding with both of the polyclonal antibodies, suggesting that this was a characteristic of the format used.

Hormone contents in peripheral tissues after correct and off-label use of growth promoting hormones in cattle: effect of the implant preparations Filaplix-H, Raglo, Synovex-H and Synovex Plus

Certain hormonal growth promoters are licensed in several beef producing countries outside the European Union (EU). Use in compliance with Good Veterinary Practice is mandatory. As risk assessment of hormone residues in animal tissues up to now has neglected potential off-label use, the present study dealt with two topics: 1) multiple treatment with the implant preparations Finaplix-H (200 mg trenbolone acetate), Ralgro (36 mg zeranol) and Synovex-H (200 mg testosterone propionate plus 20 mg estradiol benzoate) in heifers (1-fold, 3-fold and 10-fold dose), and 2) non-approved treatment of female veal calves (1-fold dose of Synovex-H or Synovex Plus with 200 mg trenbolone acetate plus 28 mg estradiol benzoate). Residues of estradiol-17beta, estradiol-17alpha, estrone and testosterone, trenbolone-17beta, trenbolone-17alpha and trendione or zeranol, respectively, were measured in loin, liver, kidney and peri-renal fat by high performance liquid chromatography/enzyme immunoassay (HPLC/EIA) after liquid-liquid extraction and solid-phase clean-up. The hormone residues in the multiple-dose experiments were dose-dependent and partially exceeded the threshold values: in the liver in one animal after 3-fold dose and in two animals after 10-fold dose of Finaplix-H, and in the liver and kidney after 3-fold and 10-fold dose of Synovex-H. Mean hormone residues in calves were mainly below those of heifers and did not infringe threshold values.

Natural sex steroids and their xenobiotic analogs in animal production: growth, carcass quality, pharmacokinetics, metabolism, mode of action, residues, methods, and epidemiology

Natural and xenobiotic compounds having sex-related actions have long been used for growth promotion and various changes in carcass quality in meat animals. The first compounds used were synthetic estrogens; however, later on a whole battery of compounds having androgenic, and progestogenic actions have also been involved. In surveying the effects of these compounds in meat-producing animals, it became clear that these drugs increase the growth rate of the treated animals and bring about changes in the carcass that are generally characterized by lower fat content and more lean mass. Extensive studies undertaken in various countries, including the European Economic Community (EEC), have shown that if used according to good husbandry practices, the meat from treated animals does not have excessive amounts of residues compared with the endogenous amount of steroid production in the animals in question and also in human beings. The banning of these compounds in the European community brought a new phenomenon of illegal or black market cocktails. These mixtures of anabolic steroids are injected into the body of the animals rather than implanted in the ears, which is the normal practice in countries where they have not yet been banned. Several screening and confirmatory methods are now available for monitoring programs. However, these programs need excessive resources in terms of manpower, funds, and proper legislation, which in underdeveloped countries is questionable, particularly in the absence of strong scientific evidence for the exercise.

High-performance liquid chromatographic separation and detection methods for anabolic compounds

The role of high-performance liquid chromatography (HPLC) in methods of analysis for anabolic compounds in biological samples is reviewed. Special attention is given to both the separation and detection of anabolic compounds. A distinction is made between on-line detection systems, such as ultraviolet detection and diode-array detection, and off-line detection methods with special emphasis on immunochemical detection methods using non-isotopic labels. A number of applications are given to elucidate the possibilities of HPLC in the analysis of anabolic compounds.

The analysis of trenbolone and the human urinary metabolites of trenbolone acetate by gas chromatography/mass spectrometry and gas chromatography/tandem mass spectrometry

The electron impact mass spectrometric properties of trimethylsilyl ether and fluoroacyl ester derivatives of trenbolone, combined or not combined with a methoxime group, are presented. Some derivatization problems were observed and were due to the formation of enol derivatives at the 3C-position in several tautomeric forms, which in their turn were not stable and lost two or four hydrogens under the conditions studied. The enolization could be minimized by carefully selecting the reaction conditions or could be prevented by the introduction of a methoxime group at the 3C-position. The limits of detection and identification of the methoxime heptafluorobutyryl ester and the methoxime trimethylsilyl ether derivative of trenbolone were determined using a mass selective detector in the electron impact mode and a triple-stage quadrupole in the methane positive chemical ionization mode. Selected reaction monitoring in tandem mass spectrometry did not improve the limit of detection, but because of the gain in selectivity did improve the limit of identification. The glucuronides of trenbolone and epitrenbolone could be identified in three urine specimens out of 200 samples in routine doping control.

Determination of 19-nortestosterone, testosterone and trenbolone by gas chromatography-negative-ion mass spectrometry after formation of the pentafluorobenzylcarboxymethoxime-trimethylsilyl derivatives

The known reaction of 3-ketosteroids with carboxymethoxylamine (to form the corresponding carboxymethoximes), followed by esterification of the carboxyl group with pentafluorobenzyl bromide, has been used to obtain derivatives of 19-nortestosterone, testosterone and trenbolone suitable for high-sensitivity detection with gas chromatography-negative-ion chemical ionization mass spectrometry. These derivatives, after further silylation of the alcoholic groups of the steroids, showed excellent chromatographic and spectrometric characteristics and were detectable in the low picogram range. The derivatization gave rise to the formation of two isomers which were distinguishable by gas chromatography. The existence of the two isomers was also confirmed by high-performance liquid chromatography. Examples of the usefulness of this derivatization procedure are given for the analysis of 19-nortestosterone, testosterone and trenbolone in meat and urine samples. By the use of immunoaffinity extraction and addition of deuterated internal standards (synthesized by isotopic exchange), the new derivatization procedure allowed a correct identification and quantitation of the steroids and reached very low detection limits [0.02 ppb (10(9] for 19-nortestosterone and testosterone, 0.06 ppb for trenbolone].

Identification and quantitation of trenbolone in bovine tissue by gas chromatography-mass spectrometry

Identification and quantitation of trace amounts of trenbolone in bovine tissue by capillary gas chromatography-mass spectrometry-selected-ion monitoring (GC-MS-SIM) has been developed. Three-phase liquid-liquid extraction using a mixture of water-acetonitrile-dichloromethane-hexane was utilized for the sample extraction from tissue. Target compounds were extracted from the tissue into the acetonitrile layer. The residue from this extraction was then subjected to solid-phase extraction by C18 and silica gel disposable cartridges using methanol-water and benzene-acetone as eluents. To overcome extensive matrix interferences, preparative reversed-phase high-performance liquid chromatographic separation was used with an octadecyl-bonded column using methanol-water as mobile phase for sample clean-up prior to GC-MS analysis. A structural analogue of trenbolone, 19-nortestosterone, was chosen as the internal standard for quantitation by GC-MS. The sample was co-injected with N,O-bis (trimethylsilyl) trifluoroacetamide-1-(trimethylsilyl) imidazole (95:5, v/v) for flash heater derivation. Identification and quantitation were simultaneously carried out by SIM of characteristic ions of the trimethylsilyl derivatives of trenbolone and 19-nortestosterone. The limit of detection for trenbolone and epitrenbolone was 0.5 ppb in muscle and liver tissue. A comparison of sensitivity and specificity between GC-MS under electron ionization in addition to positive- and negative-ion chemical ionization conditions using methane reagent gas is also discussed.

Development of a sensitive microtitration plate enzyme-immunoassay for the anabolic steroid trenbolone

The development of a competitive microtitration plate enzyme-immunoassay for monitoring trenbolone application to animals is described. 'Bridge heterology' was achieved with a rabbit antibody raised against 17 beta-trenbolone-hemisuccinate-BSA and 17 alpha-trenbolone glucuronide-alkaline phosphatase as a tracer. The required 17 alpha-trenbolone glucuronide was prepared by application of trenbolone acetate to a calf following isolation from urine by three HPLC steps. The glucuronide was linked to alkaline phosphatase by the mixed anhydride procedure. The EIA was performed by coating affinity purified sheep IgG antirabbit IgG to the microtitration plate well followed by the addition of sample, tracer and hormone-specific antibody. The absolute detection limit was less than 1 pg; 50% relative binding at approximately 3 pg which is about 20 times superior to our RIA. The sample blanks of purified extracts from urine, bile, faeces, liver and muscle were similar in both methods (EIA and RIA) and much lower than required for a reliable detection of positive samples. Assay variations were always less than 15%. For the EIA, radiolabelled trenbolone, which is not commercially available, is not necessary and according to our experience the EIA is more practicable and economic.

A specific radioimmunoassay for the detection of 19-nortestosterone residues in urine and plasma of cattle

19-Nortestosterone (Nandrolone) is illegally used as a growth promoter for meat producing animals. This work describes a radio-immunoassay (RIA) to detect, in cattle urine, Nandrolone and its metabolites. The antiserum was specific for 19-nortestosterone and its main metabolites, and to a lesser extent for Trenbolone (17 beta-hydroxyestra-4,9,11-trien-3-one). The sensitivity of this assay was 6 ug/l at 90 % B0/T binding. This assay can be used in forensic control of illegal treatment with 19-nortestosterone in meat production.

Investigations on the occurrence of non-extractable residues of trienbolone acetate in cattle tissues in respect to their bioavailability and immunological reactivity

3H-trienbolone acetate (TBA) was injected/implanted in cattle and the distribution of radioactivity in liver and muscular tissue was determined, applying rigorously standardized organic or aqueous extraction procedures, either directly or following enzymatic hydrolysis and proteolytic procedures. These steps yielded almost 100% recovery of the radioactivity and indicated that only between 5% and 15% of the total residues present was extractable with organic solvents. The remaining radioactivity was either soluble in aqueous media or stayed bound to tissue structures. Similarly processed liver tissue from a calf treated with 3500 mg TBA 68 days prior to slaughter was examined by applying radioimmunoassay for the determination of TBA/trienbolone (TBOH). Indications of the presence of trienic-steroid type residues were only obtained for fractions containing residues extractable with organic solvents.

Determination of the binding of trenbolone and zeranol to rat-liver DNA in vivo as compared to 17 beta-oestradiol and testosterone

The in vivo interactions of trenbolone and zeranol with rat-liver DNA were assayed by determining their covalent-binding indices (CBI), which correlate well with the hepatocarcinogenic potencies of chemicals. As controls, 17 beta-oestradiol and testosterone were used. Sixteen hours after intraperitoneal injection of the [3H]-labelled compounds (specific radioactivity approximately 50 Ci/mmol) the animals were sacrificed and the DNA was isolated from the livers and deproteinized by several Sevag extractions and proteinase digestion. Contaminating RNA was eliminated by pancreatic RNAase digestion. Finally, the DNA was further purified by chromatography on hydroxylapatite and by centrifugation in a CsCl gradient. Decreased CBI values after each step of purification showed that extensive purification was essential. The results obtained for the CBI were 11.4 for 17 beta-oestradiol, 4.8 for testosterone, 5.6 for trenbolone and 1.65 for zeranol, when, respectively, 15, 19, 17 and 60 micrograms/kg of anabolics were administered 16 h before the animals were killed. The CBI values for the anabolics decreased when the amount administered increased. When determined as a function of time, the CBI increased up to 24 h and decreased subsequently. After 96 h the CBI for zeranol was only 0.37 and that for trenbolone, 1.11.

Use of radioimmunoassay procedures for the determination of sex hormones in animal tissues

Radioimmunoassay methods for the determination of sex steroids and other compounds with sex hormone-like activities in various edible animal tissues and endocrine glands have been developed. Reliability of these methods, allowing quantification in a range of 10(-11) M, has been adequately demonstrated. In any case the necessary extraction procedures could be kept feasible as a result of the binding characteristics of the antisera available. When applied in respect to monitor for residues of anabolic sex hormones in edible tissues of veal calves, physiological baseline levels of some endogenous "anabolic" steroids (like testosterone, oestrogens) were established; in the case of xenobiotics residues at the scheduled time of slaughter could be quantified (trenbolone) and a regulatory method to implement the ban of diethylstilbestrol was introduced.

Differences in the biotransformation of a 17 beta-hydroxylated steroid, trenbolone acetate, in rat and cow

1. The metabolism of trenbolone acetate, 17 beta-acetoxyestra-4,9,11-trien-3-one (TBA), an anabolic compound used as a growth promoter, was compared in rat and cow. 2. [6,7-3H] TBA was injected i.v. into rats and a heifer, and bile was collected for 24 h. In both species, the bile was the major route of excretion. TBA undergoes an extensive hydrolysis to 17 beta-hydroxyestra-4,9,11-trien-3-one and the unchanged compound was not detected, but subsequent major metabolic pathways are different in the two species. 3. In the rat, oxidation of the 17 beta-hydroxyl to the 17-oxo group and hydroxylation in the 16 alpha-position are the major routes. The three major metabolites are 17 beta-hydroxyestra-4,9,11-trien-3-one, 16 alpha, 17 beta-dihydroxyestra-4,9,11-trien-3-one and 16 alpha-hydroxyestra-4,9,11-trien-3, 17-dione. 4. In the heifer, 17 alpha-epimerization is the major pathway and the main metabolite is the 17 alpha-hydroxyestra-4,9,11-trien-3-one. 5. In both species, estra-4,9,11-trien-3,17-dione and the other metabolites, resulting either from hydroxylation in 1, 2, 6 beta, 16 alpha or 16 beta positions, or from aromatization of the A ring, were minor products. 6. Overall, 60% of the 3-oxotriene structures identified in the rat bile were 17 beta-hydroxylated and the remainder were 17-keto metabolites, whereas in the heifer bile 90% were 17 alpha-hydroxylated compounds. 7. Thus, in bovine species, the major pathway is similar to those of testosterone or 17 beta-estradiol which are mainly excreted as their 17 alpha-epimers. The epimerization strongly decreases the biological potency, as with the natural 17 beta-hormones, and leads to detoxication of tissue residues.

Determination of residues of anabolic drugs in meat by gas chromatography-mass spectrometry

The residues in meat of seven estrogenic drugs used in anabolic preparations for animal production were analysed as trimethylsilyl ethers by electron-impact gas chromatography-mass spectrometry following a simple clean-up procedure. The compounds under investigation were: 17 beta-estradiol,l diethylstilbestrol,l hexestrol, dienestrol, stilbestrol, ethynylestradiol and zeranol. The method includes extractive homogenization of 10 g of meat in tetrahydrofuran, followed by liquid-liquid partition between acetonitrile and hexane and finally a chromatographic purification step on a small silica gel column. Gas chromatography was carried out on a 10-m glass capillary column coated with SE-54 using a temperature program from 100 to 250 degrees C. The capillary column was connected to the ion source by an all-glass open-split interface with a scavenger gas-line. Detection of anabolic residues was performed with selected ion monitoring on intensive ions in the mass region above m/e 400, resulting in a detection limit of 1-5 ppb (10(9)). Quantitative determinations were performed using dodecyl gallate as an internal standard applying the signal ratio of the drug and the standard.

[Determination of trenbolone and testosterone residues in meat by high pressure liquid chromatography (author's transl)]

A new method for the qualitative and quantitative determination of trenbolone and testosterone residues in meat, liver, and kidney is described. The analytical procedure consists of the following steps: homogenisation of the meat sample with tetrahydrofurane; liquid-liquid partition first between acetonitrile and hexane, then between sodium hydroxide and petroleum ether/benzene; purification of a silica gel column. The purified sample is analysed by high pressure liquid chromatography using silica gel packings. Detection and quantitative determination are performed with a fluorescence and/or a spectrophotometric detector. Fluorescence measurements are carried out applying a self-made silica gel packed flow-cell. The detection limit in meat extracts is 50 ppb for testosterone and 5 ppb for trenbolone.

[Detection of trenbolone residues in meat by thin layer chromatography and fluorimetry (author's transl)]

An new method for the qualitative and quantitative determination of trenbolone residues in meat, liver and kidney is described. The analytical procedure consists of the following steps: comminution of the meat sample; homogenisation with tetrahydrofurane; liquid-liquid partition first between acetonitril and hexane then between sodium hydroxide solution and petroleum ether/benzene; chromatography on a silica gel column. The detection on the TLC-plate is performed with 366 nm ultra violet light. The quantitative determination is carried out by means of a remission spectral fluorimeter directly on the plate. The detection limit in meat extracts was 5 ppb.

Radioimmunoassay technique for detecting urinary excretion products after administration of synthetic anabolic steroids to the horse

1. Cross-bred and thoroughbred geldings were injected with veterinary doses of various synthetic anabolic steroids. Urines collected sequentially from treated animals were analysed, following solvent extraction, by radioimmunoassay using 19-[3H]nortestosterone and an antibody raised against a 19-nortestosterone immunogen. 2. Urinary excretion of 19-nortestosterone and/or its cross-reacting metabolites was detectable for various times after administration of different nortestosterone esters, as follows: phenylpropionate (400 mg), greater than 14 days; cyclohexylpropionate (100 mg), greather than 10 days; laurate (200 mg) greater than 50 days. After administration of the parent steroid (150 mg) cross-reacting compounds were detectable in urine for ca. 3 days. 3. Urinary excretion of esters of other anabolic steroids cross-reacting with the 19-nortestosterone antibody (e.g. 1-dehydrotestosterone and trienbolone) could also be followed by analysing solvent extracts of urines by the radioimmunoassay. Cross-reacting compounds in urine after administration of 1-dehydrotestosterone undecylenate (250 mg) and trienbolone acetate (75 mg) could be detected for greater than 35 days and greather than 5 days, respectively.

Studies related to the metabolism of anabolic steroids in the horse: a gas chromatographic mass spectrometric method to confirm the administration of 19-nortestosterone or its esters to horses

A method is described to confirm the presence of 19-nortestosterone metabolites in urine after the administration of veterinary preparations of this anabolic steroid to horses. The method is based upon the detection, by gas chromatography mass spectrometry or selected ion monitoring, of an isomer of estrane-3,17-diol in the urine.