土拉霉素在猪体内残留消除规律的研究  

Determination of Tulathromycin Residues in Swine Tissues

作　　者：倪姮佳[1] 黄显会[1] 贺利民[1] 方炳虎[1] 赵永达[1] 

机构地区：[1]华南农业大学兽医学院,广州510642

出　　处：《畜牧兽医学报》2011年第4期557-561,共5页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：2010广州市科技支撑计划项目(2010Z1-E371)

摘　　要：本研究旨在分析土拉霉素在猪体内的残留消除规律并为制定休药期提供依据。采用猪颈部一次性肌内注射土拉霉素注射液,注射剂量为2.5mg.kg-1体质量,分别在给药后第0.5,5,12,18,25,36,48天,各宰杀5头取样。样品经乙腈提取,正己烷脱脂,C18固相萃取柱(SPE)净化后用高效液相色谱—串联质谱仪分析。结果显示,给药后第0.5天注射部位药物浓度最高,第36天所有组织的药物浓度均低于最高残留限量(MRL)。用WinNonlin软件分析各组织中的消除动力学参数,消除快慢依次为注射部位,肝脏,皮脂,肌肉,肺脏和肾脏,其消除半衰期(t1/2β)分别为117.06,193.14,197.60,207.64,228.99和232.61h。肺脏的药时曲线下面积(AUC)为1 220.59μg.h.g-1仅次于注射部位及肾脏,显著高于肌肉,肝脏及皮脂。由于肾脏为代谢器官,因此可确定肺脏为土拉霉素作用的靶部位。根据欧美等国家对土拉霉素制定的最高残留限量,计算得注射部位的休药期最长,为33d。结果提示土拉霉素注射液吸收迅速,体内分布广,作用时间长。建议休药期为33d。This experiment was conducted to study the tissue residues of tulathromycin in swine,preparing for the determination of the withdrawal time.Pigs received 2.5 mg·kg-1 of tulathromycin by intramuscular（i.m.） route.Animals were sacrificed at 12 hours and 5,12,18,25,36,48 days after administration.Tulathromycin was extracted from tissues by adding acetonitrile.The supernatant was defatted by adding N-hexane,then was applied to the C18 SPE cartridge.The identification was carried out by LC-MS/MS.The concentration of tulathromycin in tissues was calculated by Analyst 4.1.5 software.The results indicated that injection site held the highest residue level at 12 hours,while the concentration of tulathromycin in all of the tissues at 36 days was lower than the Maximum Residue Limit（MRL）.The pharmacokinetic parameters were estimated using WinNolin software package.The results showed that the elimination rate was injection siteliverskin＋fatmusclelungkidney,with the elimination half-life of 117.06,193.14,197.60,207.64,228.99,232.61 h respectively.Compared with other tissues,the area under the plasma concentration-time curve（AUC） in lung（1 220.59 μg·h·g-1）was greater than in muscle,liver and skin＋fat,lower than injection site and kidney.Kidney was considered as the metabolically active organ,so it suggested that lung was the target organ.According to the MRLs set by EU and USA,etc,the longest withdrawal period was suggested in injection site,33days.The results demonstrated that the absorption and distribution of tulathromyxin was wide.Besides,the active time is long.It is proposed that the withdrawal time should be 33 days after administration.

关 键 词：土拉霉素 猪 残留消除规律 休药期 

分 类 号：S859.796[农业科学—临床兽医学]