[Regeneration and functional restoration of vestibular hair cells in guinea pigs after gentamicin damage].
To investigate the possibility of regeneration and functional restoration of vestibular hair cells after toxic destruction, gentamicin (150 mg/kg per day) was given to guinea pigs subcutaneously for 10 days to induce damage of vestibular hair cells. The control animals received the same volume of saline. At 2, 4, 12 and 24 weeks after the treatment, animals were sacrificed and their vestibular organs prepared for scanning electronic microscopic study. Change of the hair cell density was studied using quantitative analysis techniques. Electronystagmogram, induced with ice water, was taken before and at 2, 4, 12, and 24 weeks after the treatment. Immature stereocillia bundles were noticed in regions with heavy hair cell loss in the utricle and crista ampullaris 2 weeks after treatment and were still visible 24 weeks after the treatment. Hair cell density (number of hair cells/100 microns basilar membrane length) decreased significantly at 12 weeks after treatment as compared with the control (P < 0.01), and showed partial recovery at 24 weeks after treatment as compared with 12 weeks after treatment (P < 0.05) which was still below normall level (P < 0.05). Vmean showed significant reduction at 4 and 12 weeks after treatment (P < 0.01), and recovery at 24 weeks (P < 0.05), which was still below the normal level (P < 0.01). SEM results indicated the potential of repair of vestibular hair cells in guinea pigs after damage which may occur 24 weeks after the damage. Quantitative analysis of hair cell density further suggests that regeneration is the mechanism of repair. The regenerated hair cells seen in this study may play a role in the restoration of vestibular function.
Wang
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Eye Ear Nose and Throat Hospital, Shanghai Medical University.
Wang
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D000818:Animals; D004584:Electronystagmography; D005839:Gentamicins / Q000633:toxicity*; D006168:Guinea Pigs; D018069:Hair Cells, Vestibular / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D009416:Nerve Regeneration; D014722:Vestibule, Labyrinth / Q000502:physiology*
D005839:Gentamicins