Characterization of trenbolone acetate and estradiol metabolite excretion profiles in implanted steers

Abstract

Exogenous growth promoters have been used in US beef cattle production for over 50 yr. The environmental fate and transport of steroid growth promoters suggest potential for endocrine-disrupting effects among ecological receptors; however, the initial excretion of steroid metabolites from cattle administered growth promoters has not been well characterized. To better characterize excretion of trenbolone acetate and estrogen metabolites, steers were assigned to 1 of the following treatment groups: control, given no implant, or treatment, administered a combination implant (200 mg trenbolone acetate, 40 mg estradiol). Blood, urine, and fecal samples were collected over the course of 112 d following implantation. Samples were extracted and analyzed by liquid chromatography tandem mass spectrometry for trenbolone acetate and estrogen metabolites. In both urine and feces, 17α-trenbolone and 17α-estradiol were the predominant metabolites following implantation. Mean concentrations of 17α-trenbolone and 17α-estradiol in feces of implanted steers were 5.9 ± 0.37 ng/g and 2.7 ± 0.22 ng/g, respectively. A best-fit model is presented to predict 17α-trenbolone and 17α-estradiol excretion from steers receiving implants. The present study provides the first characterization of both trenbolone and estrogen metabolites in excreta from implanted cattle and will help provide estimates of steroid production from feedyards in the United States.

Urinary Concentrations of Steroids in Bulls under Anabolic Treatment by Revalor-XS® Implant

“…Interestingly, these data fit well with the results achieved by Blackwell et al [20] in a similar study where a group of 8 steers received Revalor-XS implants and were followed over a period of 112 days. The urinary concentration of 17 α -TBOH was very similar in absolute concentration and trend over the same period of time.…”

“…Statistically significant different concentrations of estrone between implanted and nonimplanted animals were observed by Blackwell et al [20], though in this case the paper does not report E1 excretion during the entire trial. Differences in absolute concentrations observed between these two studies might depend on the animals (steers rather than bulls), breed, and the use of the appropriate internal standard (deuterated E1) that was applied in the present paper for E1 quantification.…”

“…For this reason, several analytical methods have been developed for the determination of hormone residues or their metabolites in samples of animal origin [12–14]. Efficient control of the illegal use of anabolic steroids must rely on the direct measurement of steroid residues, but also on their direct metabolites to take into account kinetics of elimination and metabolic patterns [15–20]. Gas chromatography-mass spectrometry (GC-MS) has played the dominant role for the detection of anabolic steroids in biological samples for many years [21–23].…”

Occurrence and Characterization of Steroid Growth Promoters Associated with Particulate Matter Originating from Beef Cattle Feedyards

“…Steroid hormones were extracted from filters and analyzed as described previously, 23 with a slight modification to separate isomers of trenbolone and estradiol. 25 Briefly, filters were extracted using liquid−solid extraction, Florisil cleanup, and analyzed by liquid chromatography tandem mass spectrometry using atmospheric pressure chemical ionization (LC−APCI− MS) with isotope dilution. Filters were spiked with 20 ng of 17β-trenbolone-d 3 , 17β-estradiol-d 5 , and melengestrol acetate-d 3 prior to extraction.…”

A critical review of the environmental occurrence and potential effects in aquatic vertebrates of the potent androgen receptor agonist 17β‐trenbolone

“…Detection of 17α‐trenbolone, 17β‐trenbolone, and/or trendione in runoff associated with cattle feedlots has been reported in several studies, typically at low nanograms per liter concentrations, with the stereoisomer 17α‐trenbolone the most commonly detected and at the highest concentrations (Table ). Trenbolone acetate is predominantly excreted from cattle as 17α‐trenbolone (∼90% of dosed trenbolone acetate), with lesser quantities of 17β‐trenbolone (∼10%) and trendione (∼1%; Blackwell et al ). This is reflected in measured environmental concentrations from a number of studies where 17α‐trenbolone was greater than 17β‐trenbolone in liquid manure (0.4–1.8 vs 0.06–0.16 μg/kg), dung (4.7–75 vs 0.5–4.2 μg/kg), soil (11.8 vs 6.1 μg/kg), final effluent water (0.3–1.5 vs 0.02–0.1 μg/L), and runoff (<0.034 μg/L vs nondetectable) from cattle feedlots where trenbolone acetate had been used (Schiffer et al ; Bartelt‐Hunt et al ; Khan and Lee ; Webster et al ).…”