This study was aimed at applying microdialysis to explore
cefquinome pharmacokinetics in thigh and plasma of healthy, neutropenic, and Actinobacillus pleuropneumoniae-infected mice. The relative recoveries (RRs) were tested in vitro by dialysis and retrodialysis and in vivo by retrodialysis. ICR mice were randomly divided into four groups: H-40 (healthy mice receiving
cefquinome at 40 mg/kg), H-160, N-40 (neutropenic mice), and I-40 mg/kg (thigh infected-mice with A. pleuropneumoniae). After
cefquinome administration, plasma was collected by retro-orbital
puncture and thigh
dialysate was collected by using a microdialysis probe with
Ringer's solution at a perfusion rate of 1.5 μL/min. Plasma and thigh
dialysate samples were assessed by HPLC-MS/MS and analyzed by a non-compartment model. The mean in vivo recoveries in the thigh were 39.35, 38.59, and 37.29% for healthy, neutropenic, and infected mice, respectively. The mean
plasma protein-binding level was 16.40% and was independent of drug concentrations. For all groups, the mean values of the free AUCinf in plasma were higher than those in murine thigh, while the elimination T 1/2β for plasma were lower than those for murine thigh.
Cefquinome penetration (AUCthigh/AUCplasma) from the plasma to thigh was 0.76, 0.88, 0.47, and 0.98 for H-40, N-40, I-40, and H-160 mg/kg, respectively. These results indicated that
infection significantly affected
cefquinome pharmacokinetics in murine thigh. In conclusion, we successfully applied a microdialysis method to evaluate the pharmacokinetics of
cefquinome in murine thigh of healthy, neutropenic, and A.
pleuropneumonia-infected mice and the pharmacokinetics of
cefquinome was obviously affected by
infection in thigh.