Objective: To study the relationship between expression of Fas protein and hair cell apoptosis following drug ototoxicity in the chicken inner ear.
Method: The damaged chicken inner ear model was developed by a subcutaneous injection of kanamycin at a daily dose of 100 mg/(kg.d) for 10 consecutive days. The Fas protein positive cells and apoptotic cells were examined by immunohistochemistry and TUNEL method at 1, 3, 7, 14, 21 days post-treatment.
Result: TUNEL positive cells were localized to luminal layer of the sensory epithelia in the basilar papilla, there were much more apoptosis cells at the seventh day post-treatment. Fas positive cells began to increase at the first day post-treatment, and expression level of Fas protein increased to its peak at the third day after the last injection. At the fourteenth day post-treatment, TUNEL positive cells decreased following a low expression of Fas protein in the basilar papilla.
Conclusion: There is a relationship between hair cell apoptosis and high expression of Fas protein in chicken inner ear following chronic kanamycin ototoxicity, Fas protein may contribute to regulate and control hair cells apoptosis.