Abstract
Previous studies have shown that the ammonia content in the brain, liver and blood was elevated in the rat under the extremely noisy condition, and that the increase in the ammonia content was inhibited by the oral administration of glutamic acid or aspartic acid.
In this paper, the ability of the brain and liver to synthesize glutamine was investigated under the extremely noisy condition.
The adult male rats were exposed to 100∼105 phon noise characterized by wide octave band spectrum for 3 hours. Glutamine synthetase activity was determined by Kennan's method.
The results were as follows:
1. Glutamine synthetase activity was inhibited by the noise exposure in the brain and liver.
2. By the oral administration of glutamic acid or aspartic acid, glutamine synthetase was not accelerated in the brain, but did in the liver.
3. The oral administration of glutamic acid or aspartic acid did not cause the decrease in glutamine synthesis in the brain and liver under the noise condition.
