Erythrophagocytosis by cells of the trophoblastic epithelium in the sheep placenta in different stages of gestation.

Erythrophagocytosis by the trophoblastic epithelial cells of the sheep placenta was studied in different stages of gestation. Light-microscopic observations showed that the erythrophagocytosis became more and more conspicuous with increasing stages of gestation. Electron-microscopically, this process appeared to take place in the same way as described for red cell destruction elsewhere. Light-microscopically, a high acid phosphatase activity could be demonstrated in the cells which took part in the process of erythrophagocytosis. Degenerating epithelial cells were found, the number of which appeared to increase with the stage of gestation. Under the electron microscope, the cytoplasm of these degenerating cells appeared to contain a diversity of crystals, myelin-like figures and irregular coarse concretions.