title: 2,3-Dihydroxybenzoic acid attenuates kanamycin-induced volume reduction in mouse utricular type I hair cells.
abstract: The aminoglycoside kanamycin is a commonly used antibiotic, but unfortunately it is oto- and nephrotoxic in large doses. The negative effects are thought to be due to the formation of free radicals which is why strong antioxidants and iron chelators like 2,3-dihydroxybenzoic acid (DHB) are of great interest. This study estimates cellular quantitative changes in the utricular macula of mice following systemic treatment with kanamycin alone or in combination with DHB. The animals were injected with either saline, kanamycin or kanamycin + DHB for 15 days and perfusion fixed three weeks after last injection. Total volume of the utricle, as well as total number of hair and supporting cells, were estimated on light microscopic sections. Total volume and mean volume of hair cell types I and II and supporting cells were estimated on digital transmission electron micrographs. Total volume of the utricular macula, hair cell type I and supporting cells decreased significantly in animals injected with kanamycin but not in animals co-treated with DHB. Hair and supporting cell numbers remained unchanged in all three groups. In conclusion, the kanamycin-induced volume reduction of type I hair cells was attenuated by DHB.
authors.affiliation: Stereology and Electron Microscopy Research Laboratory and MIND Center, Institute of Clinical Medicine, Building 1185, University of Aarhus, 8000 Aarhus C, Denmark. stig.severinsen@ki.au.dk
authors.forename: Stig A
authors.initials: SA
authors.lastname: Severinsen
authors.forename: Mette
authors.initials: M
authors.lastname: Kirkegaard
authors.forename: Jens R
authors.initials: JR
authors.lastname: Nyengaard
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D000975:Antioxidants / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D005260:Female; D006198:Hair Cells, Auditory / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D006319:Hearing Loss, Sensorineural / Q000139:chemically induced / Q000517:prevention & control*; D062385:Hydroxybenzoates / Q000494:pharmacology*; D007091:Image Processing, Computer-Assisted; D007502:Iron Chelating Agents / Q000494:pharmacology; D007612:Kanamycin / Q000009:adverse effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D046529:Microscopy, Electron, Transmission; D012444:Saccule and Utricle / Q000187:drug effects / Q000473:pathology
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D062385:Hydroxybenzoates; D007502:Iron Chelating Agents; D007612:Kanamycin; C009135:2,3-dihydroxybenzoic acid