Degenerative behavior of epithelial cells in the colonic crypt of the mouse following administration of colonic carcinogen, 1,2-dimethylhydrazine.

The degenerative behavior of cells following administration of 1,2-dimethylhydrazine was analyzed in its target organ, the distal colon of the mouse. Within 3-6 h after carcinogen treatment, an increasing number of epithelial cells in the proliferative compartment of the crypt degenerated. Degenerating cells were present most frequently as phagosomes in the neighboring epithelial cells, and infrequently as pyknotic nuclei being extruded from the epithelial lining in the crypt. Epithelial cells prelabeled with [3H]thymidine degenerated first, followed by those not prelabeled, indicating that the carcinogen-induced degeneration of cells occurred after passage of cells through the DNA synthesis phase.