磺胺间甲氧嘧啶在罗非鱼体内的药物代谢动力学及休药期
Pharmacokinetics and withdrawal period of sulfamonomethoxine in tilapia

在试验水温（28±2）℃条件下，按200 mg/kg的剂量对吉富罗非鱼单次药饵饲喂磺胺间甲氧嘧啶（SMM）后，采用HPLC法测定各组织中的药物浓度，研究SMM在罗非鱼体内的药代动力学及消除规律。结果显示,药物在各组织（血液、肌肉、肝脏和肾脏）中的最大峰质量浓度（质量分数）Cmax分别为22.66、7.13、45.50、22.77 μg /mL（μg/g）；达峰时间Tmax分别为7.52、7.02、1.00/8.00和2.00/10.00 h(Tmax1/Tmax2)；肝、肾组织中的药-时曲线有明显的双峰现象,并且第1个峰浓度高于第2个峰浓度，提示该药物在罗非鱼胃肠道中具有非齐性吸收现象；药物在各组织中（血液、肌肉、肝脏和肾脏）的消除半衰期T1/2Ke分别为5.21、4.84、14.12、6.80 h，显示SMM在罗非鱼体内代谢较快，属于较为短效的磺胺类药物；并且在肌肉和血液中的消除快于肝脏、肾脏。在（28±2）℃温度条件下，按200 mg/kg的剂量对罗非鱼连续5 d药饵饲喂SMM，研究药物的消除规律；根据罗非鱼可食性组织肌肉的残留检测结果,参考中华人民共和国第235号公告中对动物源性食品中磺胺类药物总量的MRL规定,以0.1 mg/kg为残留限量,建议休药期不低于5 d。
The pharmacokinetics and elimination of sulfamonomethoxine (SMM) were investigated after single oral administration(200 mg/kg) in GIFT tilapia (genetically improved farmed tilapia) at (28±2)℃.The concentration of SMM in tissues of tilapia was determined by HPLC.The results showed that the Cmax were 22.66,7.13,45.50 and 22.77 μg/mL (μg/g),and the Tmax were 7.52,7.02,1.00/8.00 and 2.00/10 h(Tmax1/Tmax2) in blood,muscle,liver and kidney,respectively.The bimodal phenomenon,as shown in concentration-time curve of liver and kidney,indicated that there was non-homogeneous absorption in the gastrointestinal tract of tilapia.The T1/2Ke of SMM in blood,muscle,liver and kidney were 5.21,4.84,14.12 and 6.80 h respectively,suggesting that SMM was short-acting sulfa drug in tilapia.The elimination speed was the fastest in muscle,followed by blood,kidney and liver.According to the Announcement No.235 of People’s Republic of China,the MRL in foodstuffs of animal is 0.1 mg/kg,and the withdrawal period should not be less 5 d under this experiment condition.