Kuiper H A, Noordam M Y, van Dooren-Flipsen M M, Schilt R, Roos A H
State Institute for Quality Control of Agricultural Products (RIKILT-DLO), Wageningen, The Netherlands.
J Anim Sci. 1998 Jan;76(1):195-207. doi: 10.2527/1998.761195x.
The use of veterinary medicinal products within the European Community is governed by a series of directives and regulations that describe the requirements for safety, quality, and efficacy of these products. Veterinary therapeutic use of beta-agonists has only been approved in the case of clenbuterol for bronchodilatation in horses and calves and for tocolysis in cows. No beta-agonists have been permitted in the European Community for growth-promoting purposes in farm animals. Surveillance for the presence of residues of veterinary agents in food-producing animals and meat is regulated by the Directive 86/469/EEC containing specific guidelines for sampling procedures on farms and in slaughterhouses. The level and frequency of sampling is dependent on the category of compounds and animal species. When positive samples have been identified (above certain action levels), sampling intensity is increased. Results of monitoring programs in EU member states during 1992 and 1993 for the occurrence of residues of beta-agonists in food-producing animals vary substantially with respect to the percentages of positive samples, ranging from 0 to 7%. The variability is partly explained by differences in sampling strategies, detection methods, and action levels applied. Identification of the proper matrices for sampling and detection of beta-agonists is important. In the case of clenbuterol, hair and choroid retinal tissue are appropriate tissues because clenbuterol accumulates in these matrices. A clear decrease in the use of clenbuterol in cattle has been observed in The Netherlands, Germany, Northern Ireland, and Spanish Basque Country over the last 3 yr. This is partly due to intensified surveillance activities at farms and slaughterhouses by governmental agencies and production sector organizations. There are data on human intoxication following consumption of liver or meat from cattle treated with beta-agonists. At the concentrations of clenbuterol measured in contaminated liver and meat samples, pharmacological effects may be expected in humans after consuming 100 to 200 g of product. The use of highly active beta-agonists as growth promoters is not appropriate because of the potential hazard for human and animal health, as was recently concluded at the scientific Conference on Growth Promotion in Meat Production (Nov. 1995, Brussels).
欧洲共同体对兽药产品的使用有一系列指令和法规进行管理，这些指令和法规规定了这些产品在安全性、质量和有效性方面的要求。β-激动剂在兽医治疗中的使用仅在克伦特罗用于马匹和小牛的支气管扩张以及母牛的安胎方面获得批准。在欧洲共同体，不允许将任何β-激动剂用于促进农场动物生长的目的。对食用动物和肉类中兽药残留的监测由86/469/EEC号指令进行规范，该指令包含了关于农场和屠宰场采样程序的具体指导方针。采样的水平和频率取决于化合物的类别和动物种类。当识别出阳性样本（超过特定行动水平）时，采样强度会增加。1992年和1993年期间，欧盟成员国针对食用动物中β-激动剂残留情况的监测计划结果在阳性样本百分比方面差异很大，范围从0%到7%。这种差异部分是由于采样策略、检测方法和所应用的行动水平不同所致。确定用于采样和检测β-激动剂的合适基质很重要。就克伦特罗而言，毛发和脉络膜视网膜组织是合适的组织，因为克伦特罗会在这些基质中蓄积。在过去3年中，荷兰、德国、北爱尔兰和西班牙巴斯克地区已观察到牛使用克伦特罗的情况明显减少。这部分归因于政府机构和生产部门组织加强了对农场和屠宰场的监测活动。有关于食用用β-激动剂处理过的牛的肝脏或肉类后人体中毒的数据。在受污染的肝脏和肉类样本中测得的克伦特罗浓度下，人类食用100至200克产品后可能会出现药理作用。正如最近在肉类生产生长促进科学会议（1995年11月，布鲁塞尔）上得出的结论那样，由于对人类和动物健康存在潜在危害，使用高活性β-激动剂作为生长促进剂是不合适的。
