Use of mouse vaginal and rectal epithelium to screen antimitotic effects of systemically administered drugs.

SUMMARY Effects on mitosis in mouse vaginal and rectal epithelium were used to screen antimitotic properties of drugs given i.p. Test drugs were given i.p. at time zero, podophyllin was injected at 2 hr, and the animals were killed at 8 hr. Both vagina and rectum were removed en bloc. Mitotic cells in the epithelia were counted histologically. The validity of the system was ascertained by testing drugs with known effects on the mitotic cycle. Untreated mice yielded low mitotic counts; mice receiving podophyllin alone had high counts; mice receiving cytosine arabinoside, methotrexate, nitrogen mustard, hydroxyurea, and 5-fluorouracil prior to podophyllin had low counts; and mice receiving either vinblastine followed by podophyllin or vinblastine alone showed high counts.