Experimental study of Gentamicin histopathologic effects in kidney of Oscar fish

Gentamicin is used for the infections caused by gram negative bacteria. Sever toxicity of this antibiotic through the therapeutic dosage is seen. Oscar fish (Astronotus ocellatus) was evaluated for gentamicin side effects in different therapeutic dosages. 90 red strain of this fish with 10g as mean weight were put in fives-groups in 30-litered 18 aquaria. Control one: saline injection for 5 days. Control one: saline injection for 10 days. Treatment one: 5 mg/kg gentamicin for 5 days. Treatment two: 5 mg/kg gentamicin for 10 days. Treatment three: 20 mg/kg gentamicin for 5 days. Treatment four: 20 mg/kg gentamicin for 10 days. All injections were I.P. and the volume in accordance with 1 ml/kg. This study was performed in six groups with three replicates. 24 hours after the last injection, samples were collected for pathologic effects investigation. Samples were stained with H&E. There was no histologic change and lesions in control groups. But histopathologic effects were observed in treatments. These changes are necrosis, glomerular atrophy, inflammatory cells presence, tubular dilation, hyperemia, hemorrhage and interstitial edema, hydropic degeneration in tubular cells and finally kidney necrosis or tissue destruction. By increase of dosage and duration of gentamicin use, lesions were promoted.