[Autoradiographic study of cellular structure of the epithelium of the duct of testicular epididymis of rats].

Mature rats were given intraperitoneal injections of H-3-thymidine (1 mkk/g 1-32 hours before being killed. Labelled and non-labelled mitoses and interphase cells of different types were counted in each zone of the epididymis autographs. The diurnal fluctuatiof the mitoticindex (Im) was found: form 0,19% in the day-time to 0.33% in the night at and morning hours (psmaller than 0.05). The average diurnal Im was equal to .23%-0.03. The fist wave of labelled mitoses of the epithelial cells was observed during 32 hours, tg-2 (3-5 hours) and ts(13-14 hours) were graphically calculated. The time tg-2-tm-ts was equal to 19-20 hours. Therprietal (0.87%), basal (1.87%) and oreolar (2.20%) cells of the epidermis duct labelled 1 hour after ijection of H-3-thymidine. The apical cells (3.%) were labelled 8 hours later, while the light ones were not labelled during the whole period of observation. On these grounds, the parietal, basal and oreolar cells are considered to be proliferative cells, while the light and apical ones-to be their derivatives in the epidemis epithelium. Besides, the oreolar cells may be regareded as a foreign element in the epidermis according to their morphological features and ability to migrate throughout the total depth of the epithelial layer.