Abstract
This study was designed with attention to the narcotic effect which is one of the effects of toluene on higher nervous functions. A, B and C groups of rats had been exposed respectively in 1, 000, 200, and 0 ppm of toluene for 8 hours per day for 25 weeks. In the experiment, each group was narcotized 5 times by inhalation of 20, 000 ppm of toluene. The durations of each inhalation were (1) 15 min. (2) 30 min. (3) 45 min. (4) 60 min. and (5) 75 min. in turn. The following facts were made clear by observations on the duration of convalescence and the mortality from narcotism. (1) In the duration of convalescence, there was no significant difference between three groups. (2) In the elongation of convalescence in accordance with the prolongation of inhalation, there were some significant differences between C and A or B groups. (3) In the mortality from narcotism after 5 times of inhalation, A and B groups were significantly higher than C group. (4) The rats which died at 5th inhalation required longer convalescence after 3rd and 4th inhalations than in the rats which survived at 5th inhalation. (5) There was no relation between the weight and the incidence of deaths or the duration of convalescence.
