Chemical Surveillance Branch, Veterinary Sciences Division, Agri-Food & Biosciences Institute, Belfast BT43SD, Northern Ireland, UK.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2009 May;26(5):683-91. doi: 10.1080/02652030802662738.
The administration of anabolic steroids, for the purposes of growth promotion, to food-producing animals is banned in the EU. Among the compounds covered by this prohibition is ss-nortestosterone (beta-NT). This hormone is known to occur naturally in stallions and boars, and its main bovine metabolite, alpha-nortestosterone (alpha-NT), occurs naturally in pregnant cows and neonatal calves. However, neither compound is believed to occur naturally in male cattle. During 2006, the presence of alpha-NT and, on occasion, beta-NT was confirmed in male cattle (bulls and steers) slaughtered in Northern Ireland on welfare grounds, as a result of acute injury. Subsequent investigations revealed no evidence of abuse at any of the farms involved and revealed that the phenomenon also occurred in three other regions of the EU, in similarly injured animals. A hypothetical link to release of the adrenal steroid, dehydroepiandrosterone (DHEA), in response to the stress of the injury was tested. Following the intravenous administration of DHEA to two normal steers, beta-NT (but not alpha-NT) was confirmed in the urine of one steer. Thus, it may be concluded that both beta-NT and, by implication, alpha-NT can occur naturally in male cattle (or a specific cohort thereof) in contrast to previously accepted scientific knowledge.
欧盟禁止在食品生产动物中使用合成代谢类固醇来促进生长。该禁令涵盖的化合物之一是 ss-去甲睾酮（β-NT）。这种激素已知存在于种马和公猪中，其主要的牛代谢物 α-去甲睾酮（α-NT）存在于怀孕的母牛和新生小牛中。然而，据信这两种化合物都不会自然存在于雄性牛中。2006 年，在北爱尔兰，由于急性损伤，出于福利原因被屠宰的雄性牛（公牛和阉牛）中，确认存在 α-NT，偶尔也存在 β-NT。随后的调查在任何涉及的农场都没有发现滥用的证据，并表明这种现象也发生在欧盟的其他三个地区，在同样受伤的动物中。人们测试了一种假设的联系，即受伤应激下释放的肾上腺类固醇脱氢表雄酮（DHEA）。在向两头正常阉牛静脉注射 DHEA 后，在一头阉牛的尿液中确认了 β-NT（而非 α-NT）。因此，可以得出结论，β-NT 和 α-NT（暗示）都可以自然存在于雄性牛（或其特定群体）中，这与之前的科学知识相矛盾。
