Effects of nimodipine on salicylate ototoxicity.
The purpose of this study was to examine the effects of nimodipine on salicylate ototoxicity in guinea pigs. The compound action potential (CAP) was recorded at the round window, and the cochlear blood flow (CBF) was measured simultaneously from the lateral wall of the basal turn of the cochlea by laser Doppler flowmetry. After administration of salicylate (100 mg/kg), the CAP thresholds were significantly elevated, by 5 to 20 dB (p < .05), and the CBF was significantly decreased (p < .05). After administration of nimodipine (2 mg/kg), the CAP thresholds were unchanged, but the CBF had increased significantly (p < .05), while systemic blood pressure had decreased significantly (p < .05). Simultaneous administration of both salicylate (100 mg/kg) and nimodipine (2 mg/kg) resulted in significant elevation of the CAP thresholds (p < .05), while the CBF did not decrease. These results suggest that nimodipine prevents the decrease in CBF induced by salicylate, but that nimodipine does not prevent the deterioration in the CAP.
Ochi
Kentaro
K
Department of Otolaryngology, St Marianna University School of Medicine, Kawasaki City, Japan.
Kinoshita
Hirotsugu
H
Kenmochi
Mutsumi
M
Nishino
Hirohito
H
Ohashi
Toru
T
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D001309:Auditory Threshold / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology / Q000627:therapeutic use*; D003051:Cochlea / Q000098:blood supply / Q000187:drug effects; D003638:Deafness / Q000139:chemically induced* / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D006168:Guinea Pigs; D017078:Laser-Doppler Flowmetry; D008297:Male; D009553:Nimodipine / Q000494:pharmacology / Q000627:therapeutic use*; D012039:Regional Blood Flow / Q000187:drug effects; D012405:Round Window, Ear / Q000187:drug effects; D012980:Sodium Salicylate / Q000009:adverse effects*; D013997:Time Factors; D014665:Vasodilator Agents / Q000494:pharmacology / Q000627:therapeutic use*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D002121:Calcium Channel Blockers; D014665:Vasodilator Agents; D009553:Nimodipine; D012980:Sodium Salicylate