["Autodesmosomes", desmosomes formed between apposing surface membranes of the same cell, in the human chorion laeve and amnion (author's transl)].

An unusual desmosome formation in the human amnion and chorion laeve is described. The macula adherens, found at the cell surface, forms contact zones between different parts of one and the same cell: autodesmosomes. These zones appear to seal off and trap compartments of various sizes formed by invagination of the extracellular space. Furthermore they are indistinguishable morphologically from intracellular desmosomes. Epithelial cells of the chorion laeve display autodesmosomes along the whole cell surface, however the basal surfaces of these cells are particularly rich in these structures. Amnion epithelial cells exhibit autodesmosomes on their basal surface only. These surfaces are deeply indented and the foldings, in many cases, reach into the nuclear region. In this area semidesmosomes are found. It is suggested that autodemosomes are formed by semidesmosomes which have approached and become adjacent to each other. Moreover, the presence, and relationship of the autodesmosomes to the extracellular compartments, perhaps indicate a novel metabolic regulatory function of the chorionic and amnionic cells.