Abstract

The vascular reaction such as the indirect blood pressure and the pulse rate of the tail to the noise were examined in 8 naive Sprague-Dawley rats of both sexes. The sounds used in the experiment were 1KHz and 4 KHz, 95dB pure tone generated by Nagashima Audiometry. The indirect blood pressure and the pulse rate were checked at the rat tail by Polygraph at 5 minutes interval. The results were as follows: 1. The blood pressure and the pulse rate increased maximally 5 minutes after the exposure to both sounds. 2. The blood pressure and the pulse rate returned normal range within 20 minutes after the exposure of both sounds. 3. The increment of the blood pressure and the pulse rate was greater after the sound of 4KHz than after that of 1 KHz, but it wasn't statistically significant.