| Abstract: | Eight hours after administering 4–14C‐progesterone to laying hens four radioactive metabolites could be detected in the droppings. Excretion of labelled steroid products was still continuing 192 h after the injection. In blood a relatively high level of labelled progesterone was found 8 to 24 h after application. The last traces disappeared from blood after 72 h. Compared with mammals the hen metabolises progesterone at a slower rate. Certain tissues were also examined 24 h after treatment. The adrenals showed a high level of labelled progesterone metabolites. The liver contained similar steroids as were found in the droppings. In the ovary, pituitary and skeletal muscle low or trace amounts of radioactive steroids were detected. |
