Hawkins E C, Boothe D M, Guinn A, Aucoin D P, Ngyuen J
Department of Companion Animal and Special Species Medicine, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
J Vet Pharmacol Ther. 1998 Feb;21(1):18-23. doi: 10.1046/j.1365-2885.1998.00103.x.
The purpose of this study was to determine the concentration of enrofloxacin and its active metabolite, ciprofloxacin, in alveolar macrophages (AM) and epithelial lining fluid (ELF) of the lungs in comparison to plasma concentrations in healthy dogs. Eleven dogs were given a single oral dose (5 mg/kg) of enrofloxacin. Four hours later, plasma and bronchoalveolar lavage (BAL) fluid were collected. Cells were separated from the BAL fluid and lysed for determination of drug concentrations within AM. Supernatant was used to determine concentrations of drugs in ELF. Drug assays were performed by high-performance liquid chromatography. The concentration of enrofloxacin (mean +/- SD) was 0.33 +/- 0.14 microgram/mL in plasma, 3.34 +/- 2.4 micrograms/mL in AM and 4.79 +/- 5.0 micrograms/mL in ELF. The concentration of ciprofloxacin was 0.42 +/- 0.26 microgram/mL in plasma, 1.15 +/- 1.03 micrograms/mL in AM and 0.26 +/- 0.26 microgram/mL in ELF. Mean concentrations of both drugs in AM were greater than in plasma (AM to plasma ratio, 10.3 for enrofloxacin and 4.7 for ciprofloxacin). Mean concentrations of enrofloxacin, but not ciprofloxacin, in ELF were greater than in plasma (ELF to plasma ratio, 13.5 for enrofloxacin and 0.52 for ciprofloxacin). Enrofloxacin concentrations in AM and ELF largely exceeded the MICs of the major bacterial pathogens and surpassed by about two times the breakpoint MIC of that drug, and ciprofloxacin concentrations in AM surpassed the MIC of many susceptible organisms. These results suggest that sufficient antimicrobial activity is present in AM and ELF of dogs following oral administration of enrofloxacin to be effective in the treatment of lower respiratory tract infections involving susceptible organisms.
本研究的目的是测定健康犬肺泡巨噬细胞（AM）和肺上皮衬液（ELF）中恩诺沙星及其活性代谢产物环丙沙星的浓度，并与血浆浓度进行比较。给11只犬单次口服剂量（5mg/kg）的恩诺沙星。4小时后，采集血浆和支气管肺泡灌洗（BAL）液。从BAL液中分离细胞并裂解，以测定AM内的药物浓度。上清液用于测定ELF中的药物浓度。通过高效液相色谱法进行药物测定。恩诺沙星的浓度（平均值±标准差）在血浆中为0.33±0.14μg/mL，在AM中为3.34±2.4μg/mL，在ELF中为4.79±5.0μg/mL。环丙沙星的浓度在血浆中为0.42±0.26μg/mL，在AM中为1.15±1.03μg/mL，在ELF中为0.26±0.26μg/mL。两种药物在AM中的平均浓度均高于血浆（AM与血浆的比值，恩诺沙星为10.3，环丙沙星为4.7）。ELF中恩诺沙星的平均浓度高于血浆（ELF与血浆的比值，恩诺沙星为13.5，环丙沙星为0.52），但环丙沙星并非如此。AM和ELF中的恩诺沙星浓度大大超过主要细菌病原体的最低抑菌浓度（MIC），并超过该药物断点MIC约两倍，AM中的环丙沙星浓度超过许多敏感菌的MIC。这些结果表明，口服恩诺沙星后犬的AM和ELF中存在足够的抗菌活性，可有效治疗涉及敏感菌的下呼吸道感染。
