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Updated: Aug 22, 2026
Cochlear Implantation in the Guinea Pig
Published on: June 15, 2018
Self-protection against aminoglycoside ototoxicity in guinea pigs
J A A de Oliveira1, D M Canedo, M Rossato
1Servicio de Otorhinolaryngology, University Hospital, Faculty of Medicine of Ribeirão Preto, São Paulo, Brazil.
Background:
Amikacin is a semisynthetic aminoglycoside. It acts against most of the microbial species. Amikacin limitation of the therapeutic application is the ototoxicity which promotes permanent lesions in the cochlear system. Aminoglycoside antibiotics have ototoxic potential. The target cells are preferentially the outer hair cells in the cochlear basal turns. Amynoglicoside antibiotics can quelate iron forming a complex with oxidate properties and promotes the formation of free radicals. Responsible for production of lesions in the hair cells.
Objective:
The objective of the present investigation was to determine whether the use of the aminoglycoside amikacin at small doses may lead to the occurrence of some types of resistance to or protection against ototoxicity of the drug by analyzing lesions to the organ of Corti by scanning electron microscopy.
Methods:
The study was conducted on 31 guinea pigs that were divided into 4 groups, amikacin was administered intramuscularly. The groups consisted of: group A = control group: 5 animals (10 cochleae); group B = 5 animals (10 cochleae), amikacin 20 mg/kg/day for 30 days; group C = 7 animals (13 cochleae), amikacin 400 mg/kg/day for 12 days; group d = 14 animals (26 cochleae) amikacin 20 mg/kg/day for 30 days, followed by 400 mg/kg/day for 12 days. Histological studies were performed by scanning electron microscopy. Three cochleae were excluded.
Results:
In groups A and B, the cells were normal in all cochleae, in group C there were extensive lesions of the 2 more basal turns, and in group D there was a significant reduction of lesions in the 2 more basal turns compared with group C, which had received the ototoxic dose of amikacin alone.
Conclusion:
We conclude that the non-ototoxic dose of amikacin administered before the ototoxic dose of the same antibiotic had a statistically significant protective effect on the 2 more basal turns of the guinea pig cochlea.
Insights
Pre-treating guinea pigs with a low dose of amikacin significantly protected against the ototoxicity of a higher dose. This suggests a potential strategy to mitigate amikacin-induced hearing damage.
Area of Science:
- Ototoxicity research
- Pharmacology
- Auditory science
Background:
- Amikacin, a broad-spectrum aminoglycoside antibiotic, can cause ototoxicity, damaging cochlear hair cells.
- This damage, particularly to basal turns, is linked to iron chelation and free radical formation.
- Understanding and mitigating amikacin's ototoxic effects is crucial for its therapeutic application.
Purpose of the Study:
- To investigate if low-dose amikacin confers protection against its own ototoxicity.
- To analyze cochlear lesions using scanning electron microscopy.
Main Methods:
- 31 guinea pigs were divided into four groups, receiving varying intramuscular amikacin doses and durations.
- Group A: control; Group B: 20 mg/kg/day for 30 days; Group C: 400 mg/kg/day for 12 days; Group D: 20 mg/kg/day for 30 days, then 400 mg/kg/day for 12 days.
- Scanning electron microscopy evaluated lesions in the organ of Corti.
Main Results:
- Groups A and B showed normal cochlear cells.
- Group C exhibited extensive lesions in the basal cochlear turns.
- Group D demonstrated a significant reduction in lesions compared to Group C.
Conclusions:
- Pre-administration of a non-ototoxic amikacin dose significantly protected the basal cochlear turns in guinea pigs.
- This suggests a potential therapeutic approach to prevent amikacin-induced ototoxicity.
