Enzyme-histochemically detectable glucose-6-phosphatase is present in chorion laeve trophoblasts of human fetal membranes.

The purpose of the present study was to demonstrate the presence of glucose-6-phosphatase (G6Pase) in fetal membranes from various gestational ages (20-40 weeks of gestation). Ultrastructural enzyme-histochemical analysis of G6Pase was performed using cerium and lead as capturing agents. Precipitates indicating G6Pase activity were present mainly in the endoplasmic reticulum and partly in the nuclear envelope of chorion laeve trophoblasts, but absent in amniotic epithelial cells. Stringent histochemical control experiments performed ensured specific detection of G6Pase activity. The results indicate that histochemically detectable G6Pase is present in the chorion laeve trophoblasts of human fetal membranes. This enzyme may have some physiological significance in carbohydrate metabolism in human fetal membranes and regulation of amniotic fluid glucose concentration.