Influence of glutathione s-transferase on the ototoxicity caused by aminoglycosides

The process of hair cell damage and death as a result of exposure to noise and ototoxins seems to be mediated by reactive oxygen species. Aim: To investigate the relationship between genetic polymorphisms in the Glutathione S-transferase and the susceptibility to hearing loss induced by aminoglycosides. Materials and Methods: Null genotypes were analyzed by multiplex-PCR in the DNA samples from 50 patients and 72 controls. The patients were divided into 3 groups, 10 with hearing loss using aminoglycosides (group A), 20 with hearing loss without exposure to the drug (group B) and 20 hearing individuals who used the antibiotic (group C). Study Design: Experimental. Results: Polymorphisms in the GSTM1 and GSTT1 genes were found in 16% and 42% of patients and in 18% and 53% of the control group, respectively. After statistical analysis no significant difference was observed between the control groups and A (p=0.86) and (p=0.41), controls and B (p=0.27) and (p=0.24), controls and C (p=0.07) and (p=0.47), controls and A + C (p=0.09) and (p=0.47), C and A (p=0.32) and (p=0.75), GSTT1 and GSTM1, respectively. Conclusion: Our data show that polymorphisms in GSTM1 and GSTT1 genes have no influence on the ototoxicity of aminoglycosides.