[Ototoxic effects of streptomycin in vestibular organotypic cultures].
OBJECTIVE
To investigate the ototoxic effects of streptomycin in vestibular organotypic cultures.


METHODS
F344 rats with age at postnatal day three or four were used for this study. The maculae of saccule and utricle were routinely dissected out and cultured with serum-free medium containing various dose of streptomycin for 24 hours. The ciliary turf of vestibular hair cells was stained with fluorescent phalloidin, and its nucleus was stained with to pro-3 DNA probe. The vestibular hair cells were quantitatively counted and photographed under confocal fluorescent microscope.


RESULTS
Morphological feature of vestibular hair cells were good in normal control cultures. However, the density of hair cells was decreased in evidence with increase of streptomycin sulfate concentrations. Twenty-four hours after streptomycin cultures, 0.25 mmol/L streptomycin caused a 10% hair cell missing, 50% hair cell loss from 1 mmol/L streptomycin treatment, and more than 75% hair cells gone post-3 mmol/L streptomycin cultures. After streptomycin treatment, the nuclear shrinkage and fragmentation were found in vestibular hair cells, whereas the vestibular supporting cells were normal.


CONCLUSIONS
Streptomycin induced-vestibular hair cells lesion was in a dose dependent manner with nuclear shrinkage and fragmentation. This may suggest that streptomycin leads vestibular hair cell die through apoptosis.
Yu
Dong-zhen
DZ
Department of Otorhinolaryngology, Affiliated Sixth People's Hospital, Shanghai Jiaotong University, Otorhinolaryngology Institute of Shanghai Jiaotong University, Shanghai 200233, China.
Ding
Da-lian
DL
Yin
Shan-kai
SK
Salvi
Richard J
RJ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D018069:Hair Cells, Vestibular / Q000166:cytology / Q000187:drug effects*; D009924:Organ Culture Techniques; D051381:Rats; D011916:Rats, Inbred F344; D013307:Streptomycin / Q000009:adverse effects*
D013307:Streptomycin