Ultrastructural effects of magnesium on human amniotic epithelial cells

The ultrastructure of the human amniotic epithelial cells from normal pregnancies, at term, was studied using scanning and transmission electron microscopy. The results were analysed by a stereological method which indicates the ratio between the volume of the intercellular space (R1), the microvilli (R2), and the podocytes (R3) versus the cell volume. An increase in this ratio indicates a higher structure and a facilitation of ion transport through the membrane. At low concentration (2 mM), MgSO4 increased R1 and R2 but decreased R3, whereas MgCl2 decreased R1 and R3 and had no significant effect on R2. At high concentration (10 mM), MgCl2 decreased R1 and increased R2 and R3, while MgSO4 had no significant effect on R1, increased R2, and decreased R3. The results are in part consistent with the results obtained after electrophysiological studies.