土霉素在锯缘青蟹体内的药物代谢和消除规律

采用高效液相色谱法检测土霉素,研究土霉素口灌给药途径下在锯缘青蟹体内的药代动力学。锯缘青蟹口灌给药土霉素50 mg/kg后,其血浆、肌肉和肝胰脏中的药峰浓度分别为16.78±1.98 mg/L、9.39±2.12μg/g和32.12±6.12μg/g,达峰时间分别为4 h、8 h和4 h。血浆中土霉素浓度-时间关系曲线符合一级吸收的二室开放动力学模型。土霉素在锯缘青蟹体内分布广泛,其表观分布容积(Vd)为2.129 L/kg;分布半衰期(t1/2α)和消除半衰期(t1/2β)分别为3.200 h和47.856 h,总体清除率(CLs)为0.063 mL/(kg.h)。肌肉和肝胰脏中土霉素浓度与时间关系的药动学参数采用统计矩原理分析,其消除半衰期(t1/2 z)分别为60.145 h和71.009 h,总体清除率(CLz)分别为0.054 g/(kg.h)和0.037 g/(kg.h)。土霉素在精巢和卵巢中达峰时间分别为8 h和12 h,峰浓度分别为9.83μg/g和10.26μg/g。给药后24 d时,血浆、肌肉、肝胰脏、精巢和卵巢中土霉素含量都已低于0.10μg/g。土霉素在锯缘青蟹体内消除比较缓慢。

On the metabolism and elimination of oxytetracycline in mud crab (Scylla serrata) following oral administration

This paper deals with the pharmacokinetic study of oxytetracycline(OTC) following oral administration carried out in mud crab,Scylla serrata.Hemolymph and tissue concentrations of OTC were examined by high performance liquid chromatogram(HPLC).After oral administration with a dose of 50 mg/kg,the peak OTC concentrations in hemolymph,muscle and hepatopancreas were 16.78±1.98 mg/L,9.39±2.12 μg/g and 32.12±6.12 μg/g respectively.Time taken to reach peak OTC concentration were 4 h both in hemolymph and hepatopancreas and 8 h in muscle.The profile of hemolymph concentration vs.time was in accordance with the open two-compartment pharmacokinetic model of first-order absorption.OTC distributed widely in mud crab and the apparent volume of distribution(Vd) was 2.129 L/kg.The half-life time of distribution(t1/2α)and elimination(t1/2β)were 3.200 h and 47.856 h respectively.The total body clearance(CLs)was 0.063 mL/(kg·h).The pharmacokinetic parameters of the profile between OTC concentrations and time in muscle and hepatopancreas were analyzed by statistical moment theory.The elimination half-life time(t1/2z) in muscle and hepatopancreas were 60.145 h and 71.009 h respectively,and the total body clearance(CLz)were 0.054 g/(kg·h) and 0.037 g/(kg·h) respectively.Time taken to reach Peak OTC concentration in spermary and ovary were 8 h and 12 h respectively,and the peak OTC concentrations were 9.83 μg/g and 10.26 μg/g respectively.24 days after oral administration,the OTC concentrations in hemolymph,muscle,hepatopancreas,spermary and ovary were all lower than 0.10 μg/g.In summary,OTC eliminated relatively slowly in mud crab.