[Studies on human endometrial regeneration]

The structural characteristics and site of origin of the resurfacing uterine lining, as well as the influence of ovarian hormonal stimuli on the reparative processes of experimentally injured endometrium in women, were studied by means of cytology, light microscopy and electron microscopy. In exfoliative cytology, the cells which seemed to be derived from the surface layer showed nuclear enlargement, anisonucleosis, hyperchromasia and prominent nucleoli. The repair of the uterine surface was completed within 4 days following the first 24 hours, after mechanically inducing trauma. After complete reepithelialization, regeneration of the secretory endometrium appeared even more markedly delayed than that of proliferative endometrium. The mechanism of recovery of the denuded surface was due to a progressive epithelial outgrowth from the mouths of basal glands. The resurfacing cells were epithelial in nature. Stromal cells which appeared to project between gland stumps and take part in the reepithelialization by a process simultating metaplasia were not recognized. It was suggested that the newly formed surface lining was derived from the stumps of residual basal glands.