Background and Objectives : Quinolone-induced arthropathy is an unusual toxic effect observed in juvenile animals of multiple species. Such toxic effects are usually found in joint cartilages. The reports of chondrotoxic potential of quinolones
in
juvenile animals were mainly performed in weight bearing joints such as hips and knees. The purpose of this study was to investigate the morphological changes in the incudomalleolar joint of immature rats dosed with ciprofloxacin, and to draw
relationship between the incudomalleolar joint pathology and hearing.
Materials and Methods : An experimental group of 21-day-old rats
were administrated intraperitoneally with 200 mg ciprofloxacin/kg for 10
days. The hearing threshs of the control and experimental animals were
determined with auditory brainstem response (ABR). Their ossicles were
obtained and fixed, and we observed them with light microscopy (LM)
and transmission electron microscopy (TEM).
Results : The ABR threshs were increased in the ciprofloxacin
administrated group, and the increased latency of the first waves were
identified in the ciprofloxacin administrated group, but there were no
differences in the interval of wave I-III. The LM findings of
incudomalleolar joint in the ciprofloxacin administrated group showed
cartilage lesions such as disrupted articilar surface, irregular cellularity of
the chondrocytes, matrix swelling, cleft formation, decreased matrix
staining. The TEM findings of the incudomalleolar joint cartilage in the
ciprofloxacin administrated group showed decreased bundle-like matrix
and cell process, condensed nucleus, and vacuolated cytoplasm.
Conclusion : From the results of recent works and the present study,
we suggest that ciprofloxacin may induce morphological changes in the
incudomalleolar joint, and that such morphological changes may induce
conductive hearing loss.
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