Cytophotometric DNA analysis of rectal mucosa of patients with ulcerative colitis.

Cytophotometric DNA analysis of rectal mucosa was carried out in 11 patients with ulcerative colitis, in attempt to determine the proliferative activity of rectal mucosa. There was no significant difference in the mean DNA value, modal DNA value, total variation of DNA content and population of over 3c cells of rectal mucosa between controls and the patients. However, the differential determination of the proliferative activity in the upper, middle and lower thirds of the crypt disclosed that a population of over 3c cells in the upper and middle thirds of the crypt was significantly larger in the patients with longstanding disease than in the controls.