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[Methylcobalamin, antagonist to transient ototoxic action of gentamicin]
1Department of Otorhinolaryngology, Renji Hospital, Second Medical University, Shanghai 200001.
Objective:
To explore whether is methylcobalamin effective in prophylaxis of AmAn ototoxic action.
Method:
We attempted to use a single injection of gentamicin(125 mg/Kg b.i.w.) to make an animal (guinea pig) model of transient sensory disturbance of hearing, and by a series observation of the changes in ECochG to find out the antagonistic action of methylcobalamin which was simultaneously given to animals(1 mg/Kg, i.m.) followed injection of gentamicin.
Result:
1. The transient ototoxic action of gentamicin may cause delay of latency and diminution of amplitude of CAP N1 and N2 in animals with a single injection of gentamicin. Though the interval between N1 and N2 prolonged, the changes were still within normal ranges. 2. By contrast, the changes of delay at N1 and N2 as mentioned above were significantly improved in animals administered simultaneously with methylcobalamin.
Conclusion:
It indicated that in addition to the improvement of physiologic function of nerve fibres, methylcobalamin may be also an agent to prevent the transient ototoxic action of gentamicin. Due to methylcobalamin acts as a methyl donor, it participates the synthesis of SAM (S-adenosylmethionine) and thus products GSH(Glutathion SH), the latter may inhibit ototoxic side-effects of gentamicin.
Insights
Methylcobalamin effectively prevents gentamicin-induced ototoxicity in guinea pigs by improving nerve fiber function. This vitamin B12 derivative may inhibit gentamicin
Area of Science:
- Neuroscience
- Pharmacology
- Ototoxicology
Context:
- Gentamicin is a common antibiotic with known ototoxic side effects.
- Ototoxicity can lead to hearing disturbances.
- Preventive strategies against ototoxicity are clinically significant.
Purpose:
- To investigate the prophylactic efficacy of methylcobalamin against gentamicin-induced ototoxicity.
- To evaluate the impact of methylcobalamin on auditory nerve function following gentamicin exposure.
Summary:
- Gentamicin administration in guinea pigs induced transient hearing disturbances, evidenced by delayed latency and diminished amplitude in Compound Action Potential (CAP) N1 and N2.
- Simultaneous administration of methylcobalamin significantly ameliorated these gentamicin-induced changes.
- Methylcobalamin demonstrated an antagonistic effect on gentamicin's ototoxic action.
Impact:
- Methylcobalamin shows potential as a protective agent against transient ototoxicity.
- The mechanism may involve methylcobalamin's role as a methyl donor, aiding S-adenosylmethionine and Glutathione synthesis, which counteracts ototoxic effects.
- Findings suggest methylcobalamin could be a valuable adjunct in preventing antibiotic-induced hearing loss.