Effects of impulse noise on cortical response threshold and inner ear activity of succinic dehydrogenase and acetylcholinesterase in guinea pigs.
The effects of impulse noise (firecrackers at 170 dB SPL, 1, 10, 20 rounds) on auditory cortical response threshold (CRT) and activity of succinic dehydrogenase (SDH) and acetylcholinesterase (AchE) in the inner ear were studied in 37 guinea pigs. The results showed that extent of damage in the cochlea was related to amount of exposure to the noise. Exposure to 10 rounds resulted in temporal threshold shift (TTS); to 20 rounds the result was permanent threshold shift (PTS). For the period when TTS existed, inverse correlation was noticed between enzyme activity change and CRT shift. The correlation could not be established when PTS was induced. The results suggest that the pathomechanism of PTS was more complex than that of TTS. The significance of the results is discussed.
Zhai
S
S
Institute of Otorhinolaryngology, General Hospital of PLA, Beijing, PR China. Zhaisq@plagh.com.cn
Jiang
S
S
Gu
R
R
Yang
W
W
Wang
P
P
D000110:Acetylcholinesterase / Q000032:analysis*; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology*; D003051:Cochlea / Q000201:enzymology* / Q000293:injuries / Q000503:physiopathology; D004396:Coloring Agents; D004781:Environmental Exposure; D005500:Follow-Up Studies; D006168:Guinea Pigs; D006199:Hair Cells, Auditory, Inner / Q000201:enzymology / Q000648:ultrastructure; D018072:Hair Cells, Auditory, Outer / Q000201:enzymology / Q000648:ultrastructure; D006309:Hearing / Q000502:physiology; D006311:Hearing Disorders / Q000201:enzymology / Q000503:physiopathology; D009411:Nerve Endings / Q000201:enzymology / Q000648:ultrastructure; D009622:Noise / Q000009:adverse effects; D011897:Random Allocation; D020127:Recovery of Function; D013385:Succinate Dehydrogenase / Q000032:analysis*
D004396:Coloring Agents; D013385:Succinate Dehydrogenase; D000110:Acetylcholinesterase