Abstract
1. Aminopterin demonstrated a notable inhibiting effect upon the growth of the Yoshida sarcoma, especially in cases which received the repeated intraperitoneal injection of 0.05mg. per 100g. body weight. Non-specific changes in the tumor cells after the injection, such as caryorrhexis and vacuolar degeneration were described. These cellular changes were obtained also by subcutaneous injection of the compound.
2. Other 13 folic acid antagonists including Methopterin and folic acid demonstrated neither remarkable cellular changes nor inhibiting effect.
Acknowledgements. The author wishes to express his gratefulness to the Lederle Laboratories, Dr. Sugiura, and the Iatrochemical Institute for supplying the compounds which made this study possible. This study was supported by the “Grant in Aid for Fundamental Scientific Research” of the Ministry of Education.
