The effect of oestro¬ gen and progesterone on the incorporation of tri¬ tiated thymidine

Summary. The incorporation of tritiated thymidine into the uteri of immature mice in organ culture was assessed by autoradiography and liquid scintillation spectrometry. Oestrogenand progesterone, alone or combined, stimulated an increase in the incorporation of tritiated thymidine, indicating that DNA synthesis is occurring in vitro. Pro-gesterone alone stimulated incorporation of label into stromal and epithelial cells, but the combination of progesterone and oestrogen stimulated the labelling of epithelial cells more than of stromal cells