Illicit treatments in cattle and urinary 6beta-hydroxycortisol/cortisol ratio.

The control of the illegal use of anabolic agents in cattle is still an exciting analytical challenge and new screening tests are demanded to reduce the number of false negative results. In humans, the urinary ratio between 6β-hydroxycortisol (6βOH-F) and cortisol (F) is used in vivo as a probe of the cytochrome P4503A activity, an enzyme mainly involved in endogenous and exogenous steroid metabolism. At present, no data on the urinary 6βOH-F/F ratio in cattle are available. From 2003 to 2005 several experiments were carried out in cattle with dexamethasone (DEX) and steroid hormones; urine samples were collected, once a week, all throughout the trials and 6βOH-F and F concentrations measured in both control and treated animals. Preliminary results, obtained with ELISA and RIA analyses (6βOH-F and F, respectively) showed a statistically significant (P<0.01) difference in 6βOH-F/F ratio between control (0.53-1.04) and DEX orally treated (2.3 – 3) animals.