The influence of immune stress induced by Escherichia coli lipopolysaccharide on the pharmacokinetics of danofloxacin in broilers

This study aimed to determine whether the challenge from Escherichia coli (E. coli) lipopolysaccharide (LPS) affects the pharmacokinetics of danofloxacin in broilers. Twenty 1-day-old Arbor Acres (AA) broilers were equally and randomly divided into 2 groups. When the chickens were 23, 25, 27, and 29 days old, E. coli LPS (1 mL; 0.5 mg/kg body weight [BW]) and sterile saline (1 mL) were intraperitoneally injected into the two groups. After the last injection, danofloxacin was given to all chickens by gavage at the dose of 5 mg/kg BW. Then serum and plasma samples at each time point were collected through the wing vein. Danofloxacin concentrations in plasma were detected through the high-performance liquid chromatography (HPLC) method and subjected to noncompartmental analysis using Phoenix software. The levels of chicken interleukin-1β (IL-1β) and corticosterone (CORT) in serum were measured by the Enzyme-linked immunosorbent assay (ELISA) kit. In addition, after the collection of plasma or serum samples, 7 chickens (31 days of age) in each group were killed to calculate the organ indices. Compared with the control group, the challenge of LPS significantly decreased the parameters of AUC(0-∞), C(max), and t(1/2λz) and increased the parameters of T(max) and λz. Additionally, in the LPS group, the absorption time of danofloxacin was prolonged; however, the elimination was accelerated, which resulted in reduced internal exposure.