THE PRESENCE OF PLATELET-DERIVED ENDOTHELIAL-CELL GROWTH-FACTOR IN HUMAN ENDOMETRIUM AND ITS CHARACTERISTIC EXPRESSION DURING THE MENSTRUAL-CYCLE AND EARLY GESTATIONAL PERIOD

Decidualized tissues are characterized by the intensive outgrowth of the microvasculature. Several angiogenic factors are assumed to be involved during the drastic change in the vasculature occurring in the process of decidualization. We examined the possible role of platelet-derived endothelial cell growth factor (PD-ECGF), a known angiogenic factor, during the process of early decidualization in humans. The expression of PD-ECGF in human endometrium was demonstrated by Western blot analysis, a marked increase being found in decidualized endometrium. Immunohistochemical staining showed that PD-ECGF immunoreactivity was present mainly in decidualized endometrial stromal cells. We established a primary cell culture of human endometrial stromal cells which were differentiated into decidualized cells in vitro by the addition of progesterone. In this cell culture system, progesterone augmented the expression of PD-ECGF in a dose-dependent fashion. The addition of progesterone also resulted in an increased release of prolactin, a well-known marker for decidualization. These findings suggest that PD-ECGF may play a physiological role as a possible angiogenic factor in the process of decidualization of human endometrium.