THE EFFECTS OF OESTROGEN ON THE CELL CYCLE IN EPITHELIAL AND CONNECTIVE TISSUES OF THE MOUSE UTERUS

Abstract

SUMMARY The duration of stages of the cell cycle in the uterine epithelial and stromal tissues of ovariectomized mice was estimated by the labelled mitosis method. In untreated animals the mean duration of the S phase (DNA synthesis) was 10·5 h in the glandular and luminal epithelium. Oestrogen treatment shortened it to 6 h in both tissues. In the endometrial stroma of progesterone-treated mice the duration of S was 8 h; when oestrogen was given it increased slightly. The generation times estimated under steady-state conditions were 270,156 and 383 h respectively in the lumen, glands and stroma of untreated mice. After oestrogen stimulation the responses became highly synchronized.