An experimental study of vascular damage in estrogen-induced embolization

Temporal sequences of estrogen-induced embolization were studied in both in vivo and in vitro models. Infusion of the estrogen compound into rat mesenteric artery caused local spherocytosis and severe rapid degeneration of endothelial cells, followed by injury to the underlying muscle cells and fibroblasts. These changes were regarded as mainly the results of the embolization effect of conjugated estrogen. A study of cultured vascular endothelial cells suggested narrow margins of effective drug concentrations for cell damage. Also, nuclear disintegration with relative sparing of cytoplasmic constituents seemed to be characteristic of estrogen-induced cell damage in both in vivo and in vitro models.