[Negative surface charge of human trophoblast and its biological role (author's transl)]

The negative charges on the various trophoblast was investigated, in order to cast light on the biological roles, by electron microscopy using cationized ferritin as an ultrastructural marker, in comparison with surface glycoprotein. The following results were obtained: 1. The surface glycoprotein distributed on the trophoblastic plasma membrane forming regularly situated aggregates, 15 to 20 millimicron in diameter separated by 50 to 100 millimicron from neighboring ones. 2. The negative charge on the cell surface was distributed in two different configurations: A strongly negative part and weakly negative one. 3. The placental villi were revealed to carry an extremely high level of negative surface charge. 4. One maternal lymphocyte in a first trimester pregnancy was calculated to carry a 5.9 x 10(-11) Coulomb negative surface charge. 5. In a simplified model, the electronic repulsive force between the lymphocyte and placental villus was calculated as 5.7 x 10(-4) Newton, showing that the electronegative charge on human trophoblast was strong enough to repel the negatively charged lymphocyte against the lymphocyte gradient. 6. For villi from spontaneous abortion with mild degeneration, the surface glycoprotein was observed to make prominent aggregates on the trophoblastic surface in concomitance with the reduced negative surface charge. 7. With the observation by electron microscopy, The complete mole differed essentially from the partial mole in that former resembled normal villi while the later spontaneous abortion.