Blood–brain barrier permeability to enrofloxacin in Pengze crucian carp (Carassius auratus var. Pengze)

BACKGROUND: Enrofloxacin (ENR) is a kind of quinolone antibiotic that is most widely used antimicrobials in veterinary practice, and possesses both a broad spectrum antimicrobial activity against a range of bacteria and adverse effects towards plants and animals. OBJECTIVES: This study was conducted to explore the permeability of blood–brain barrier (BBB) to ENR and brain injury based on crucian carp orally administrated with high dose of ENR. METHODS: Juvenile Pengze crucian carp were treated with half lethal dose (LD(50)) or safe dose (SD(50)) of ENR. BBB permeability was determined by evaluating ENR contents detected by HPLC and evens blue contents estimated by confocal laser scanning microscope. Brain damage was evaluated by measuring protein and mRNA contents of related molecules with western blotting and qPCR. RESULTS: Data indicated that ENR destroyed BBB structure of crucian carp and enhanced permeability of the biological barrier, resulting in more ENR crossed BBB and induced brain damage of crucian carp. CONCLUSIONS: This data indicated that ENR can induce brain damage of crucian carp through destroying BBB structure and enhancing permeability.