Effect of noise level on the Met-enkephalin content of the guinea pig cochlea.
Using a highly sensitive and specific radioimmunoassay for Met-enkephalin, we have monitored in two series of experiments the changes of the Met-enkephalin content of guinea pig cochleas following a 60 min exposure to different intensities of white noise (70 dB SPL, 90 dB SPL, 110 dB SPL). Our results indicate that the Met-enkephalin content was significantly lower after noise exposures than after exposure to the silence of a sound attenuated chamber. After a stimulation at 70 dB SPL, the levels of Met-enkephalin were 70% (series I) and 61% (series II) of those obtained after a period of silence. After a 110 dB SPL stimulation, these values fell to 41% (series I) and 55% (series II) of those in silence. These results strengthen the hypothesis that enkephalins are olivocochlear neuroactive substances. They suggest that the enkephalin-containing lateral olivocochlear system discharges with noise stimuli of moderate intensity.
Eybalin
M
M
I.N.S.E.R.M.-U.254, Université de Montpellier II, CHR Hôpital St. Charles, France.
Rebillard
G
G
Jarry
T
T
Cupo
A
A
D000161:Acoustic Stimulation; D000818:Animals; D001306:Auditory Pathways / Q000378:metabolism / Q000502:physiology; D003051:Cochlea / Q000378:metabolism* / Q000502:physiology; D004744:Enkephalin, Methionine / Q000378:metabolism* / Q000502:physiology; D006168:Guinea Pigs; D009622:Noise; D011863:Radioimmunoassay
D004744:Enkephalin, Methionine