Progesterone in the uterus. VI. On the question of the in vitro progesterone metabolism in human endometrium and myometrium.

Human endometrial and myometrial tissue pieces were incubated with radioactively labeled progesterone in nutrient medium for 20 min., 1 hr and 2 hrs. The only compound extracted from the tissue pieces and the nutrient fluids was identified to be progesterone by TLC, chemical reactions and crystallization experiments. Radiometabolites could not be detected in the tissue pieces and in the nutrient fluids under the experimental conditions applied (10(-7) M 1,2-3H-progesterone in the incubation medium). This result is comparable with recent findings on the in vitro progesterone metabolism by rat uterine tissue.