Influence of evoked HSP70 expression on 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.


CONCLUSIONS
HSP70 expression induced by pre-exposure to noise protects the hearing function of the cochlea in guinea pigs.
Wang
Xu-Wu
XW
Department of Otolaryngology, 456 Hospital of PLA, Ji'nan 250031, China.
Wang
Xi-Jun
XJ
Song
Jiang-Shun
JS
Chen
He-Xin
HX
Man
Yu-Hong
YH
D000818:Animals; D003051:Cochlea / Q000502:physiology*; D004594:Electrophysiology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D006168:Guinea Pigs; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D006309:Hearing / Q000502:physiology*; D009622:Noise; D013997:Time Factors
D018840:HSP70 Heat-Shock Proteins