The effects of physical environmental factors on thiamine metabolism have been investigated by some workers, but definite results were not obtained. The objective of this study was to investigate thiamine metabolism in rat brain and liver under certain physical conditions.
Adult male rats were exposed to 4 experimental physical conditions: noise, cold, horizontal rotation and vertical vibration. For the noise condition, two types of noise were used at 100 to 110 phon: one was characterized by wide octave band spectrum and the other was a loud bell. The temperature in the cold condition was -10±2°C. The centrifugal force of holizontal rotation was 2.8 rcf. For the vertical vibration, two types of vibration in frequency (420cpm and 690cpm) were used, and the amplitude of earch was 10mm. The durations of exposure to cold, rotation and vibration were 3 hours. In noise conditions, one was formed by ON-fraction of 15 minutes. OFF-frction of 15 minutes and ON-fraction of 15 minutes, and the other was made by a continuous exposure of 30 minutes.
The results were as follows:
Unedr noise, cold and rotation, significant changes in thiamine contents of brain and liver could not be observed.
Under a 690cpm vibration, the contents of total and ester thiamine in the brain and free thiamine in the liver decreased significatly, but no definite influence was detected under 420cpm vibration.
Therefore, investigating histochemicaly the adrenal cortex by Zinsser's stain method in the vibration group, the fucsinophyle granules of zona fasciculata were increased. The hypertrophy of the same layer was observed only under 420cpm vibration, but not seen under 690cpm vibration.