Ultrastructural Observations on Angiogenetic Cell Formation and Differentiation Towards Vascular Endothelium in Human Placental Villi

Abstract

Human placental villi undergo extensive morphogenesis during the earliest stages of development, and the predominant cell type of chorionic vilh core, with a well-developed basement membrane separating the trophoblast from their stroma, were indifferent mesenchymal cell and fibroblast-like cell types with well-developed GER cistemae and Golgi complex (Demir et al., 1987.) The basic cell types of villous core are of indifferent mesenchymal cell variety. In the early periods of pregnancy, they show a differentiation towards whole variety of villous stromal cells, some of them constituting the early angioblastic masses (Demir and Erbeng4 1987; Demir et al., 1989) and forming the blood vessels. These new cells are fibroblasts, reticulum cells, pericytes, endothelial cells, Hofbauer cells and embryonal plasma cells. They construct all stromal architecture.