抄録
Although numerons researchers have reported results of the polyphasic physiological responses in noise environments, experimental criteria on the some from the standpoint of physiological responses is scarce.
From the results of our studies on the physiological responses in a noise environment we can conclude that the main location of physiological damage by noise may be in the higher centres.
Next central metabolic changes in a noise environment were investigated. Significant results were that the ammonia content in the brain was increased remarkably during noise exposure but not so during other stress exposures.
In the present study the increase of the ammonia content of the brain was investigated as an indicator to exposure. Adult male rats were exposed to 70-110 phon white noise for 2 hours. Immediately after the animals were killed by decapitation. The brain was rapidly removed and hemogenized in ice cold 10% trichloroacetic acid with glass homogenizers. Determination of the amount of ammonia was made by Conway's method using the Seligson-Hirahata's apparatus.
The following results were obtained:
When the intensity of exposed noise was above 80 phon the ammonia content of the brain increaed significantly.
