抄録
The amount of virus introduced into the respiratory tract of mouse by our standard inhalation procedure has been calculated on the basis of two experiments.
Firstly, the dilution extent of virus suspensions which will kill the 50% of mice by inhalation was compared with that obtained by instillation. The result indicated that 1/10 to 1/16 amount of virus was effective at the time of inhalation when compared to the value obtained at the time of instillation.
Secondly, P32 labeled virus was prepared and the actual counts found along the whole respiratory tract and also in the lung were compared between two groups of mice infected by these two procedures. Here the value 1/10 was obtainable.
Further it was shown that by the procedure of instillation, around 50 per cent of the theoretically introduced amount of virus was detectable in the naso-tracheo-broncho-alveolar tree. On the basis of these figures it was concluded that 1/500 ml. of virus solution which was put into the vaporizer was inhaled in the respiratory tract of mouse by means of our standard inhalation procedure.
Uniform distribution of virus among animals has been suggested by inhalation contrary to the fairly deviated distribution of the inoculum from animal to animal at the time of instillation.
From this observation, the difference of death tendency observed between two procedures have been elucidated.
