OBJECTIVE: To investigate the effect of evoked heat shock protein 70 (HSP70) expression on the hearing function of the cochlea in guinea pigs. METHODS: Guinea pigs were divided into pre-exposure group (pre-treated with white noise exposure at 100 dB SPL for 45 min) and none pre-exposure group. Auditory brainstem response (ABR) thresholds were recorded at 12, 60 and 108 h after the animals in both groups were exposed to loud white noise (125 dB SPL, 90 min). RESULTS: HSP70 expression was evoked by pre-treatment with white noise (100 dB SPL, 45 min). There was no significant difference of ABR thresholds between the 2 groups (P>0.05) at 12 h after exposure to loud noise, while ABR thresholds became lower in pre-exposure group than in none pre-exposure group (P<0.01) at both 60 and 108 h. In the pre-exposure group, ABR thresholds at 108 h were significantly lower than that measured at 60 h (P<0.05), but which was not the case in none pre-exposure group. CONCLUSION: HSP70 expression induced by pre-exposure to noise protects the hearing function of the cochlea in guinea pigs.
OBJECTIVE: To investigate the effect of evoked heat shock protein 70 (HSP70) expression on the hearing function of the cochlea in guinea pigs. METHODS:Guinea pigs were divided into pre-exposure group (pre-treated with white noise exposure at 100 dB SPL for 45 min) and none pre-exposure group. Auditory brainstem response (ABR) thresholds were recorded at 12, 60 and 108 h after the animals in both groups were exposed to loud white noise (125 dB SPL, 90 min). RESULTS: HSP70 expression was evoked by pre-treatment with white noise (100 dB SPL, 45 min). There was no significant difference of ABR thresholds between the 2 groups (P>0.05) at 12 h after exposure to loud noise, while ABR thresholds became lower in pre-exposure group than in none pre-exposure group (P<0.01) at both 60 and 108 h. In the pre-exposure group, ABR thresholds at 108 h were significantly lower than that measured at 60 h (P<0.05), but which was not the case in none pre-exposure group. CONCLUSION: HSP70 expression induced by pre-exposure to noise protects the hearing function of the cochlea in guinea pigs.