Int. Adv. Otol. 2011; 7:(2) 215-224

Does Aluminum Cause Ototoxicity in Rats?
Erol Selimoglu, Tuba Bayindir, Mustafa Iraz, Mehmet Gul, Yesim Durgun, Tamer Erdem, Tayyar Kalcioglu
Inonu University, Faculty of Medicine, Departments of Otolaryngology, Malatya, Turkey

Background: Aluminum (Al) is a nonessential and toxic metal to which humans are frequently exposed. Except one study which revealed adverse effects of serum Al levels on the auditory functions in hemodialysis patients, there is not any other study on the effects of Al on auditory functions.

Study design: Acute and chronic effects of Al on rat auditory system were investigated in that randomized controlled study. Methods: Forty five male Sprague-Dawley rats were included. Rats were divided into six groups according to the dose and route of Aluminum chloride (AlCl3): in groups A (n=7), B (n=9), and C (n=9), intraperitoneally (IP) AlCl3 was injected in doses of 1mg/kg, 5mg/kg, and 80mg/kg, respectively; in control group (group K, n=6), saline was injected IP; in groups D (n=7) and E (n=7) oral AlCl3 was administered in doses of 5mg/kg, and 50mg/kg, respectively. OAE measurement was performed for four times in IP AlCl3 groups; before and on the 1st, 7th, and 14th days after aluminum administration. In oral group OAE measurement was performed before and on the 1st, 2nd, and 3rd months after aluminum administration. The distortion product otoacoustic emissions (DPOAEs) at 2f1-f2 were recorded and analyzed. Histological  xamination of the cochlea was performed.

Results: DPOAE measurements of all groups before and after AlCl3 administrations were not statistically different. Histological examination revealed normal stria vascularis, spiral ganglion and organ of corti in all groups.

Conclusion: Neither acute nor chronic administration of AlCl3 in aforementioned doses and routes caused neither clinical nor histological ototoxicity.