The mitogenie action of ovarian hormones on the uterine and the vaginal epithelium during the oestrous cycle in the rat: A radioautographic study

Mitotic parameters (S phase duration and generation time) have been studied in the vaginal and the endo-uterine epithelium, at different stages of the oestrous cycle in the rat. The double labelling technique with [3H]thy-midine was employed. Both in the vaginal basal epithelial layer and in the endometrial epithelium the cellular proliferation rate was maximal during dioestrus, whereas the longest generation times were observed at oestrus. This finding is in accordance with the recently proposed pattern of oestro-gen secretion in this species. Maximal growth rate in the vagina was delayed as compared with the uterine epithelium