Calvarese S, Rubini P, Urbani G, Ferri N, Ramazza V, Zucchi M
Istituto Zooprofilattico Sperimentale dell'Abruzzo, Teramo, Italy.
Analyst. 1994 Dec;119(12):2611-5. doi: 10.1039/an9941902611.
19-Nortestosterone (19-NT) is one of the mostly recurrent anabolic agents on the black market of illicit drugs. Dexamethasone (DEXA) is licensed for therapy in veterinary practice but its misuse, although often suspected, has seldom been demonstrated. The excretion of 19-NT and DEXA is well documented when the compounds are administered independently but poor information is available in literature for instances when both drugs are administered as a mixture. To evaluate a radioimmunoassay (RIA) for anabolic residues in urine, blood and faeces, the effect of the simultaneous administration and the subsequent elimination of the two drugs, two animals were injected (4 times) with 19-NT and another two (4 times) with 19-NT-DEXA. After preparation and a sequential clean-up on C18 and alumina columns, the samples were analysed by means of a specific 19-NT radioimmunoassay kit and an anti-DEXA antibody. Detection limits for both drugs were 0.5 ppb in blood samples and 2.0 ppb in urine and faecal samples. After the final treatment, positive 19-NT results were recorded at 14 and 21 d in urine and faecal samples, respectively. In the same matrices, positive DEXA values were found at 11 and 28 d, respectively. In the same matrices, positive DEXA values were found at 11 and 28 d, respectively. Urinary excretion was the main metabolic path both for 19-NT and DEXA; only 30% of the residues were excreted via the faeces. The simultaneous injection of DEXA and 19-NT increased the urinary excretion of 19-NT; however, the excretion of 19-NT via faecal matter was similar for both groups.
19-去甲睾酮（19-NT）是非法药物黑市上最常出现的合成代谢药物之一。地塞米松（DEXA）在兽医实践中有治疗许可，但尽管经常被怀疑存在滥用情况，却很少得到证实。当单独使用这两种化合物时，19-NT和DEXA的排泄情况已有充分记录，但对于两种药物混合使用的情况，文献中提供的信息很少。为了评估一种用于检测尿液、血液和粪便中合成代谢残留物的放射免疫分析（RIA）方法，对两种药物同时给药及随后消除的影响，给两只动物注射（4次）19-NT，另外两只动物注射（4次）19-NT-DEXA。在制备并依次在C18和氧化铝柱上进行净化后，使用特定的19-NT放射免疫分析试剂盒和抗DEXA抗体对样品进行分析。两种药物在血液样本中的检测限均为0.5 ppb，在尿液和粪便样本中为2.0 ppb。在最终处理后，尿液和粪便样本中分别在第14天和第21天记录到19-NT的阳性结果。在相同基质中，分别在第11天和第28天发现DEXA的阳性值。尿液排泄是19-NT和DEXA的主要代谢途径；只有30%的残留物通过粪便排出。同时注射DEXA和19-NT增加了19-NT的尿液排泄量；然而，两组通过粪便排出的19-NT量相似。
