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Updated: Oct 13, 2026
Cochlear Implantation in the Guinea Pig
Published on: June 15, 2018
[Effects of streptomycin on ionic currents in isolated outer hair cells of guinea pig cochlea]
1Department of Otorhinolaryngology, Union Hospital of Tongji Medical University, Wuhan.
Abstract:
The effects of streptomycin on ionic currents in outer hair cells isolated from the cochlea of guinea pig were investigated using a whole-cell recording patch-clamp technique. External application of streptomycin (1 mmol/L) caused a decrease of the potassium currents and calcium currents, respectively. The half-maximal inhibition concentration of streptomycin checking the voltage-dependent calcium currents was 56.08 mumol/L, and the ratio of maximal inhibition 21.71%. The present results demonstrate that streptomycin partially irreversibly blocks the voltage-dependent calcium currents in dissociated outer hair cells of guinea pig cochlea in a concentration-dependent manner. The effects of streptomycin of the potassium currents may be, at least in part, the result of the inhibition of Ca2+ influx. It suggests that the inhibition of Ga2+ influx may be one of the ototoxic mechanisms of streptomycin on outer hair cells.
Insights
Streptomycin partially blocks calcium and potassium currents in guinea pig outer hair cells. This inhibition of calcium influx may contribute to the ototoxicity of streptomycin.
Area of Science:
- Ototoxicology
- Cell Physiology
- Neuroscience
Context:
- Outer hair cells (OHCs) are crucial for hearing sensitivity.
- Streptomycin is an aminoglycoside antibiotic known for its ototoxic side effects.
- Understanding the cellular mechanisms of ototoxicity is vital for developing protective strategies.
Purpose:
- To investigate the effects of streptomycin on ionic currents in isolated guinea pig outer hair cells.
- To determine the concentration-dependent effects of streptomycin on voltage-dependent calcium and potassium currents.
- To elucidate the role of calcium influx inhibition in streptomycin-induced ototoxicity.
Summary:
- Streptomycin (1 mmol/L) reduced potassium and calcium currents in isolated guinea pig outer hair cells.
- The half-maximal inhibitory concentration (IC50) for voltage-dependent calcium currents was 56.08 µmol/L, with a maximal inhibition ratio of 21.71%.
- Streptomycin partially and irreversibly blocked voltage-dependent calcium currents in a concentration-dependent manner, suggesting calcium influx inhibition as a key ototoxic mechanism.
Impact:
- Provides mechanistic insights into streptomycin-induced ototoxicity at the cellular level.
- Highlights the role of voltage-dependent calcium channels in outer hair cell function and vulnerability.
- Informs potential therapeutic interventions aimed at mitigating streptomycin's damaging effects on hearing.
