On the detectability of anabolic steroids in horse urine [proceedings].

This research paper presents the detectability of various anabolic steroids in horse urine after they were administered in veterinary doses, using the antibody raised against 19-nortestosterone.

Antibody Characterization and Experiment Conduct

• The experiment used an antibody against 19-nortestosterone 3-(0- carboxymethyl)oxime-bovine serum albumen in Soay ewes, developed by Jondorf in 1977. The objective was to monitor the excretion of diverse anabolic steroids administered to horses.
• Research was conducted on both cross-bred and thoroughbred geldings managed under standard conditions of feeding and exercise.
• These horses were intramusically injected with different forms of 19-nortestosterone including 19-nortestosterone laurate, 19-nortestosterone phenylpropionate, and 19-nortestosterone cyclo-scanned image of page 297P amongst others. Each horse was administered different doses of the drug.
• The horse urine samples were collected before and after the steroids were administered, and stored in deep freeze (-20°C) until they were needed for analysis.

Sample Analysis and Findings

• The horse urine samples were then thawed, adjusted to pH 9, and extracted with chloroform/methanol mix in rotary separators for 20 minutes before analysis.
• The extraction was analyzed using the radioimmunoassay method that requires a biological sample to contain more than 100 pg of 19-nortestosterone equivalent for efficient analysis.
• The research findings show that 19-nortestosterone’s urinary fate lingers for more than 45 days in some cases. The measurement of 19-nortestosterone in urine after administration could be followed for over 45 days—the extent of binding depression still remained equivalent to 100-250 pg of 19-nortestosterone.
• It is important to note that the detectability of an anabolic steroid post-administration is not solely dependent on the unmodified, de-esterified parent steroid excretion.
• Further comparison of anabolic steroids showed that the urinary detectability for different forms of 19-nortestosterone, like phenylpropionate and the cyclohexyl-propionate, were detectable for about 15 and 10 days respectively.
• Other steroids such as tricnbolone acetate could be detected for more than 5 days and 1-dehydrotestosterone undecylenate could be detected for more than 21 days post-administration.

Conclusion

The study concludes the detectability of different anabolic steroids in horse urine when administered in veterinary doses, a crucial element in monitoring the use of these compounds in horse racing and other competitive events.