Schlupp A, Anielski P, Thieme D, Müller R K, Meyer H, Ellendorff F
Institute for Animal Science Mariensee, Federal Agricultural Research Centre, 31535 Neustadt, Germany.
Equine Vet J. 2004 Mar;36(2):118-22. doi: 10.2746/0425164044868620.
The beta2-agonist clenbuterol is commonly administered for therapeutic purposes in the horse, but its use an an anabolic agent is illegal. Clenbuterol can be detected in blood and urine for a relatively short period after administration and detection in hair could enhance the analytical range and be used to determine the history of clenbuterol application.
That detection in mane or tail hair is possible over an extended period.
Four horses received 0.8 microg clenbuterol hydrochloride/kg bwt b.i.d. for 10 days. Four other horses were used as untreated controls. Blood, urine, mane and tail hair samples were taken on Day 0 (before) and 5, 10, 30, 35, 40, 60, 90, 120, 150 and 360 days after start of treatment. Gas chromotography/high resolution mass spectrometry (GC/HRMS) was developed for clenbuterol analysis: limit of detection was 0.2 pg/mg; intra-assay repeatability limit r = 0.06 (confidence level 95%); interassay repeatability limit r = 0.03 (confidence level 95%). Prior to treatment, clenbuterol was absent from all samples analysed.
Clenbuterol was detectable as early as Day 5 in tail and mane hair of Segment 1 (0-20 mm from the roots) and was maximal on Day 90. However, as time progressed, shift into lower 20 mm segments was observed. On Day 360, the maximum concentration (up to 21 pg/mg) was located in Segment 13, i.e. 26-28 cm from roots of hair. Clenbuterol was not detectable in blood or urine after Day 30. Mane and tail hair results were very similar.
The study showed that the beta-agonist clenbuterol can be found in mane and tail hair of horses after extended periods.
It will be possible to detect clenbuterol in breeding and show horses where anabolic drugs have been used illegally to improve conformation. This method may also be helpful to monitor therapeutic clenbuterol treatment.
β2 激动剂克伦特罗通常用于马匹的治疗目的，但其作为合成代谢剂使用是非法的。给药后，克伦特罗在血液和尿液中可被检测到的时间相对较短，而在毛发中检测克伦特罗可扩大分析范围，并用于确定克伦特罗的用药史。
在较长时间内可在马鬃毛或尾毛中检测到克伦特罗。
四匹马按每千克体重 0.8 微克盐酸克伦特罗的剂量，每日两次给药，持续 10 天。另外四匹马作为未治疗的对照。在治疗开始前的第 0 天以及治疗开始后的第 5、10、30、35、40、60、90、120、150 和 360 天采集血液、尿液、马鬃毛和尾毛样本。开发了气相色谱/高分辨率质谱法（GC/HRMS）用于克伦特罗分析：检测限为 0.2 皮克/毫克；批内重复性限 r = 0.06（置信水平 95%）；批间重复性限 r = 0.03（置信水平 95%）。在治疗前，所有分析样本中均未检测到克伦特罗。
在第 1 段（距根部 0 - 20 毫米）的尾毛和马鬃毛中，早在第 5 天就可检测到克伦特罗，在第 90 天达到最高值。然而，随着时间推移，观察到其向较低的 20 毫米段转移。在第 360 天，最高浓度（高达 21 皮克/毫克）位于第 13 段，即距发根 26 - 28 厘米处。在第 30 天后，血液或尿液中未检测到克伦特罗。马鬃毛和尾毛的结果非常相似。
该研究表明，β 激动剂克伦特罗在较长时间后可在马的马鬃毛和尾毛中被发现。
有可能在种马和参赛马中检测到非法使用合成代谢药物以改善体型的情况。该方法也可能有助于监测克伦特罗的治疗性用药。
