[Histochemical study of carbohydrate metabolism in fetal membranes]

By means of histochemical methods, we investigated the location of carbohydrates and the carbohydrate metabolism in the fetal membranes. It was shown that the often extremely intense vacuolisation of the trophoblast cells is based on the excessive accumulation of glycogen. Perhaps the reason, that glycogen could not be shown up to now, is that it lies in an undetectable state. From our enzyme histochemical results, we conclude that out of glycogen, lipids, phospholipids, also mucopolysaccharides and collagen for the extracellular matrix are synthetized. Furthermore we assumed, that glycogen is partly depolymerized and transported towards the amniotic epithelial with a liquid flow. After uptake by the fibroblasts, it is used for the further production of extracellular matrix. The carbohydrate component of glycoproteins and proteoglycans were classified by the use of lectin-binding-studies. The amniotic epithelial cell does not only release glycoproteins and proteoglycans on the apical cell surface but also into the intercellular space. These substances are probably related to the intercellular liquid flow. 3H-labelled glucose passed through this intercellular space and transcellular through the amniotic epithelium.