Persistence of Amethopterin in Normal Mouse Tissues.

Abstract

The persistence of amethopterin in normal mouse tissues following various injn. regimens was investigated. Neither the size of the dose (0.5-20.0 mg./kg.) nor the route of injn. of amethopterin had any effect on the high retention level in the liver through a 3-wk. period. There was a slight decrease in the kidney level during the 3-wk. period in all groups of mice. The subsequent injn. of citrovorum factor had no detectable effect after 24 hrs. on tissue retention, but the serum level rose appreciably. The antimetabolite present in the liver 24 hrs. to 14 days, and in 1 case 8 mos., after injn. of amethopterin was found to be identical with amethopterin in 3 chromatographic systems.