Histochemistry and role of nitric oxide synthase in the amphibian (Ambystoma tigrinum) inner ear.
Nicotinamide adenine dinucleotide phosphate reduced-diaphorase (NADPH-d) histochemistry was investigated in the axolotl (Ambystoma tigrinum) inner ear. Hair cells showed an intense NADPH-d reaction; afferent neurones also stained but less intensely than hair cells. Effects of NG-nitro-L-arginine (L-NOARG) on the basal discharge and mechanical responses of semicircular canal afferent neurones recorded extracellularly were also studied. L-NOARG (1 mu M) diminished the basal discharge and the response of afferent neurones to sinusoidal mechanical stimuli to 45 +/- 6.4% and 65 +/- 5.3% (mean +/- SEM) of control value, respectively. These findings suggest that production of nitric oxide (NO) by hair cells and probably also by afferent neurones contributes to the basal discharge and the response of afferent neurones to mechanical stimuli.
Facultad de Medicina, Universidad Autonoma de Puebla, Mexico.
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Flores
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Leon-Olea
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Vega
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Soto
D000557:Ambystoma / Q000378:metabolism*; D000818:Animals; D007758:Ear, Inner / Q000166:cytology / Q000201:enzymology*; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005071:Evoked Potentials / Q000187:drug effects; D018069:Hair Cells, Vestibular / Q000187:drug effects / Q000201:enzymology; D006651:Histocytochemistry; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009475:Neurons, Afferent / Q000187:drug effects / Q000201:enzymology; D009476:Neurons, Efferent / Q000187:drug effects / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D019335:Nitroarginine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D019335:Nitroarginine; D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase