Dürsch I, Meyer H H, Karg H
Institut für Physiologie des Forschungszentrums für Milch und Lebensmittel Weihenstephan, Technische Universität München, Freising, Germany.
J Anim Sci. 1995 Jul;73(7):2050-3. doi: 10.2527/1995.7372050x.
Two independent experiments were carried out to determine whether Clenbuterol is accumulated by pigmented tissues. In the first experiment, unpigmented and pigmented rats were injected two times with 5 micrograms of Clenbuterol subcutaneously and the eyes were analyzed after 63 h of withdrawal by enzyme immunoassay. Only pigmented rat eyes showed a clear accumulation of Clenbuterol (68.1 to 81.5 ng/g), whereas the eyes of unpigmented treated rats demonstrated levels similar to the negative controls (< .27 ng/g). In the second experiment, two Holstein-Friesian calves were fed with .8 microgram of Clenbuterol/kg BW two times a day (therapeutic dose) in milk replacer and black and white hair was collected separately before, during, and after the treatment. The hair was analyzed with an enzyme immunoassay that provided blanks less than 1.0 ng/g and a mean recovery of 67%. This experiment showed an accumulation of Clenbuterol in both sets of hair, but a definitely higher accumulation of Clenbuterol in black (pigmented) hair than in white hair. The black/white quotient amounted to approximately 50 at 1 wk after treatment. Results of these experiments favor the use of the eye as well as the hair for residue analysis but in case of hair, variation of pigmentation in different animals must be considered.
进行了两项独立实验，以确定克伦特罗是否会在色素沉着组织中蓄积。在第一个实验中，对未着色和着色的大鼠皮下注射两次5微克克伦特罗，停药63小时后通过酶免疫测定法分析眼睛。只有着色大鼠的眼睛显示出克伦特罗有明显蓄积（68.1至81.5纳克/克），而未着色处理大鼠的眼睛显示的水平与阴性对照相似（<0.27纳克/克）。在第二个实验中，给两头荷斯坦-弗里生犊牛每天两次在代乳品中饲喂0.8微克/千克体重的克伦特罗（治疗剂量），在处理前、处理期间和处理后分别收集黑白毛发。用酶免疫测定法分析毛发，该方法的空白值小于1.0纳克/克，平均回收率为67%。该实验表明两组毛发中均有克伦特罗蓄积，但黑色（有色素沉着）毛发中的克伦特罗蓄积量明显高于白色毛发。处理后1周时，黑/白商约为50。这些实验结果支持将眼睛和毛发用于残留分析，但对于毛发而言，必须考虑不同动物色素沉着的差异。
