title: A comparative study of intratympanic steroid and NO synthase inhibitor for treatment of cochlear lateral wall damage due to acute otitis media.
abstract: We studied the damage to the cochlear lateral wall induced by otitis media and the therapeutic effects of intratympanic administration of steroid and nitric oxide (NO) synthase inhibitor. In Sprague-Dawley rats, right middle ear cavities were inoculated with lipopolysaccharide, followed after 30 min by intratympanic administration of dexamethasone, NOS-inhibitor or PBS. Twenty-four hours after lipopolysaccharide inoculation, cochlear blood flow was measured by laser-Doppler flowmetry. Prostaglandin E(1) was topically applied to the round window membrane of the right ear and changes in cochlear blood flow were calculated. Changes of cochlear blood flow were significantly different among the three groups. Increases in cochlear blood flow following PGE(1) application were higher in the group that received NOS-inhibitor. Electron microscopic examination revealed that changes in the stria vascularis were less severe in rats treated with dexamethasone or NOS-inhibitor. Our results show the effectiveness of intratympanic dexamethasone or NOS-inhibitor in treating cochlear lateral wall damage caused by otitis media.
authors.affiliation: Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa, Nagoya 466-8550, Japan. michsone@med.nagoya-u.ac.jp
authors.forename: Michihiko
authors.initials: M
authors.lastname: Sone
authors.forename: Hideo
authors.initials: H
authors.lastname: Hayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Tominaga
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000578:Amidines / Q000008:administration & dosage*; D000818:Animals; D003051:Cochlea / Q000098:blood supply / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D003907:Dexamethasone / Q000008:administration & dosage*; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005260:Female; D006574:Heterocyclic Compounds, 2-Ring / Q000008:administration & dosage*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010033:Otitis Media / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014432:Tympanic Membrane / Q000098:blood supply / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology
chemical_list: C407360:7-chloro-3-imino-5-methyl-2-azabicyclo(4.1.0)heptane; D000578:Amidines; D004791:Enzyme Inhibitors; D006574:Heterocyclic Compounds, 2-Ring; D003907:Dexamethasone; D019001:Nitric Oxide Synthase