Morphological changes in rat aortic endothelial cell line stimulated by endothelin.

We have reported that endothelin (ET)-1 activates interleukin (IL)-6 production in rat aortic endothelial cell line (WAE-1 cell). In this experiment, we investigated the morphological changes induced by ET-1 in cultured WAE-1 cells. The cells were treated with ET-1 for 8 h or 24 h, and then compared with untreated cells by light and electron microscopies. The WAE-1 cells treated with ET-1 for 8 h showed remarkable alterations as following: by light microscopic observation, the cells were enlarged and filled with many vesicles in the cytoplasm, and by electron microscopic observation, the cells showed the increases of nuclear membrane infoldings, increased density of chromatin granules just inside the nuclear membrane, and multivesicular bodies in the cytoplasm. These morphological changes were hardly observed in WAE-1 cells-treated with ET-1 for 24 h. It was suggested that ET-1 stimulated DNA synthesis and secretion of cytoplasmic products in WAE-1 cells.