The effect of croton oil and carcinogens on mitosis and the deoxyribonucleic acid content of cervical epithelial cells.

Studies on the deoxyribonucleic acid (DNA) content of normal nondividing plant and animal nuclei revealed that it is quite stable in interphase, showing little variation from cell to cell (4, 21). This is in sharp contrast to the wide varia tion and generally larger amounts of DNA found in tumor cells (1,17, 20,31) and normal cells dur ing periods of rapid growth (32). Preliminary ex periments utilizing endocervical strings containing methylcholanthrene resulted in the prompt ap pearance in vaginal smears of cells containing in creased amounts of nuclear DNA. The present study was undertaken to determine whether this was a specific response to the carcinogen or simply the result of increased cellular proliferation, and to compare these changes with DNA alterations in early and advanced cancer.