Quinazoline CB 3717 and CB 3703 inhibition of folate retention and metabolism in Ehrlich ascites carcinoma cells and some organs of the host-mouse.

Disturbances in folate metabolism in Ehrlich ascites carcinoma-bearing mice caused by 2 quinazoline-antifolates are described. They are manifested by diminished retention in tumour cells and the host-liver of injected radioactive folate and by a decreased extent of its conversion to coenzymatic, polyglutamate forms. Kidney retention of folate was also affected by either quinazoline, showing a severalfold decrease in mice treated with CB 3703, and a 2-fold increase in those treated with CB 3717. Kidney folylpolyglutamate content was also greatly reduced.