[Low dose of ouabain protects injury of spiral ganglion neurons in vitro].
OBJECTIVE
To evaluate the protective effect of low dose ouabain on injury of cultured spiral ganglion neurons evoked by trophic factors deprived and to explore the mechanism.


METHODS
Spiral ganglion neurons were cultured in vitro for 7 days, and then exposed to Neurobasal medium + B27 supplement, Neurobasal medium only or Neurobasal medium + 10 nmol/L ouabain, respectively. After 48 h exposed to different medium, spiral ganglion neurons were stained by FITC labeled Annexin-V and PI, then apoptosis index were calculated using fluorescent microscope and flow cytometry, respectively. In addition, spiral ganglion tissues were cultured for 48 h to evaluate dendrite growth of spiral ganglion neurons in each group. Immunocytochemistry were performed to detect the level of Bcl-2 in each group at 6 h and 12 h.


RESULTS
Spiral ganglion neurons exposed to Neurobasal medium +10 nmol/L ouabain have a similar apoptosis index compare with that of Neurobasal medium + B27 supplement, but a much lower apoptosis index than that of Neurobasal medium only. In addition, dendrite growth of spiral ganglion neurons exposed to Neurobasal medium +10 nmol/L ouabain was much longer than that of Neurobasal medium only. Bcl-2 level increased in spiral ganglion neurons exposed to Neurobasal medium + 10 nmol/L ouabain at 6 h.


CONCLUSIONS
Low dose of ouabain protects injury of spiral ganglion neurons evoked by trophic factors deprived in vitro. This effect may mediated by increasing the level of Bcl-2.
Wei
Yonghao
Y
Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
Xiao
Hongjun
H
Jiang
Yuanming
Y
Yang
Chen
C
Zheng
Na
N
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D010042:Ouabain / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013136:Spiral Ganglion / Q000187:drug effects* / Q000473:pathology
D010042:Ouabain