[Regionally different activity of enzymes within placentones of human term-placentas. Histochemical and biochemical investigations (author's transl)].

After a short summarizing review earlier histological and first histochemical investigations on the functional morphology of placentones results of histochemical and biochemical studies about thirteen enzymes are presented. Histochemical and biochemical investigations demonstrate that the placental villi situated in the centers of the circulation-units show enzyme-patterns which only differ quantitatively not qualitatively from those of the villi situated in the periphery. Specific acitivity is found to be weaker in the central villi. The results confirm our former histological investigations which gave evidence that the villi situated in the centers of placentones were relatively immature compared to those of the periphereal areas. The centers of the placentones therefore are to be considered for regions of regeneration and growth whilst in the periphery placental metabolism and maternofetal exchange takes place.