Aminoglycosides activate oxygen metabolites production in the cochlea of mature and developing rats.
The ototoxicity of antibiotics, particularly of aminoglycosides, is a well-known undesirable side effect which may be based on a free radical mechanism. We studied the effect of different antibiotics in the production of reactive oxygen species in freshly isolated cochleas of mature and 2-10 weeks old developing rats. Phorbol myristate acetate induced the release of reactive oxygen species after a lag time close to 30 s and declined back to basal values in 10-20 min. The rate of reactive oxygen species production correlated inversely to the age in 2-10 weeks old rats. The study of a set of antibiotics showed that a very low concentration of gentamicin and streptomycin (10-100 ng/ml) enhanced the effect of phorbol myristate acetate. At the above-indicated concentrations, ciprofloxacin did not modify phorbol myristate acetate-induced activation. These results show the enhancement by aminoglycosides of reactive oxygen species production in cochlear tissues, particularly in developing rats.
Lopez-Gonzalez
M A
MA
Unit of Pediatric Otorhinolaryngology, Virgen del Rocio University Infantile Hospital, Sevilla, Spain.
Delgado
F
F
Lucas
M
M
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D003051:Cochlea / Q000187:drug effects / Q000378:metabolism*; D004357:Drug Synergism; D005839:Gentamicins / Q000494:pharmacology; D066298:In Vitro Techniques; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013307:Streptomycin / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D005839:Gentamicins; D017382:Reactive Oxygen Species; D002939:Ciprofloxacin; D013755:Tetradecanoylphorbol Acetate; D013307:Streptomycin