騒音環境下における脳内水分動態

抄録

The experiments were undertaken to clarify the relation between the water metabolism and the noisy environment as compared with cold. We used 100 to 105 phon noise characterized by wide octave band spectrum at room temperature (20±2°C). The temperature in the cold condition was 10±2°C. The adult male rabbits were arranged in 4 groups of 5 animals each; control, exposure to cold, one or repeated exposure to noise. The rabbits were exposed to cold for 90 minutes, and to noise for 3 hours once or 8 hours daily during one month. Thereafter, the brain was removed and separated into 7 parts; cerebrum, cerebellum, upper and lower part of mesencephalon, interbrain, medulla oblongata, and pons. The water content was determined by Hatschek's method.
The results were as follows:
1) In the control group, the free water content in cerebrum and cerebellum were higher than that in medulla oblongata, pons and upper-part of mesencephalon. The bound water content in cerebrum and cerebellum were lower than that in medulla oblongata and upper-part of mesencephalon.
2) Under the cold condition, the bound water content decreased in upper-part of mesencephalon. The changes in the free water content were not significant.
3) Under the noise condition, the free water content decreased and the bound water content increased in interbrain. Besides, in the repeated exposure, the bound water increased in cerebrum and pons.