恩诺沙星在健康及巴氏杆菌感染鸡体内的药物代谢动力学研究

健康及巴氏杆菌感染鸡 (10CFUC4 8- 1多杀性巴氏杆菌 /只鸡 ,im)按 5mg/kg恩诺沙星单次im后 ,采用反相高效液相色谱法检测用药后不同时间点的血浆药物浓度。结果表明 ,恩诺沙星在健康及巴氏杆菌感染鸡体内的消除均符合二室开放模型。巴氏杆菌感染可显著加速鸡体内恩诺沙星的消除 ,推测可能与感染鸡体内巴氏杆菌裂解后产生的内毒素有关。内毒素可刺激骨髓产生大量白细胞 ,而恩诺沙星又恰恰能在吞噬细胞中富集 ,且在富集后可迅速向周围炎性组织中释放 ,因此导致血中药物浓度下降。提示在应用恩诺沙星预防、治疗细菌性疾病时 ,利用其在健康鸡体内的药物动力学参数指导临床用药 ,有时是不适宜的。

Pharmacokinetics of Enrofloxacin in Healthy and Pasteurella multocida Infected Chicken

Pharmacokinetics of single intramuscular administration at a dose of 5mg/kg enrofloxacin were studied in healthy and Pasteurella multocida infected chicken. The levels of enrofloxacin in plasma were measured using RP HPLC. The results showed that plasma profile of enrofloxacin in healthy and Pasteurella multocida infected chicken following im dosing were best described by two compartment model. The cause that the clearance of enrofloxacin from plasma in chicken infected with Pasteurella multocida were more quickly than that in control animals might be correlated with endotoxin released from Pasteurella multocida . Endotoxin could stimulate bone marrow to produce large amounts of leukocytes in which enrofloxacin could accumulate and rapidly leaked from leukocytes into infective tissues, as a subsequence, the residual enrofloxacin in plasma of chicken was reduced. Therefore, one should be cautious to recommend dosage regimen of enrofloxacin for clinical application based on the its disposition in healthy animals.