Attenuation of streptomycin ototoxicity by tetramethylpyrazine and its effect on K⁺ channels in the outer hair cells of guinea pig cochlea.

Abstract

In order to elucidate the mechanism underlying the attenuation of streptomycin ototoxicity by tetramethylpyrazine (TMP), the present study investigated the effect of TMP on the outward K(+) current in the outer hair cells of guinea pig cochlea. Sixty guinea pigs were divided into 6 groups randomly. Auditory brainstem response (ABR) was used to observe the change in thresholds and to evaluate ototoxicity induced by streptomycin. Whole-cell patch-clamp technique was used to observe the effect of TMP on outward K(+) current in isolated outer hair cells. The results showed that TMP attenuated the threshold shift caused by streptomycin and increased the amplitudes of Ca(2+)-sensitive K(+) current [I(K(Ca))] in the outer hair cells. The present data suggest that TMP displays anti-ototoxicity induced by streptomycin. The augmented amplitudes of I(K(Ca)) of the outer hair cells induced by TMP may be one of the mechanisms underlying its ototoxicity-attenuating effect.

• Authors: Hao Tang, Gui-Ying Cui, Li-Juan Shi, Qing-Hua Gao, Yu Cao
• Journal: Sheng li xue bao : [Acta physiologica Sinica] (Sheng Li Xue Bao) Vol. 59 Issue 4 Pg. 534-8 (Aug 25 2007) ISSN: 0371-0874 [Print] China
• PMID: 17700974 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Potassium Channels
• Pyrazines
• tetramethylpyrazine
• Streptomycin

Topics

• Animals
• Auditory Threshold
• Cochlea (cytology)
• Evoked Potentials, Auditory, Brain Stem
• Guinea Pigs
• Hair Cells, Auditory, Outer (drug effects)
• Patch-Clamp Techniques
• Potassium Channels (metabolism)
• Pyrazines
• Streptomycin (toxicity)