[Histophysiological characterisation of chorion. Histological, histochemical, and electron-microscopic investigations (author's transl)].

Histological, histochemical, and electron-microscopic techniques were used to investigate the chorion in 15 women over the first four to eight weeks of normal pregnancy. Evidence was produced to maximum enzyme activity and lipoid accumulation between the sixth and eighth weeks. These findings were confirmed by ultrastructural observation. Data were collected on active exchange in x-cells. That exchange together with manifest delta 5-3-beta hydroxysteroid-dehydrogenase were found to cause not only oxidative processes, but, with some reasonable probability, synthesis of steroid hormones in the chorion, as well.