Histopathological effect of norfloxacin on gill arch cartilages in common carp(Cyprinus carpio)

Tissue distribution and histopathological influence of norfloxacin on gill arch cartilages were investigated in 75 day old common carp(Cyprinus carpio) using the methods of microassay in the standard agar diffusion in which Escherchia coli ATCC25922 was used as experimental bacterium.The results showed that norfloxacin has powerful affinity with cartilagess of juvenile carp.There was the maximum level of norfloxacin in cartilage,followed by liver,then in muscles.The carp bathed in Norfloxacin for 5 consecutive days(30 min per day) at a dose of 25,150 or 900 mg/L had detectable histopathological lesions in gill arch cartilages,e.g cartilage cell necrosis,dissolved,vacuolated at a dose of 150 mg/L,which indicating that more attention should be paid when fluoroquinolones treatment is administrated.