Estrogen increases bone marrow-derived endothelial progenitor cell production and diminishes neointima formation.

Background: Estrogens improve endothelial function and accelerate reendothelialization after vascular injury via largely unknown mechanisms. Bone marrow-derived endothelial progenitor cells (EPCs) are thought to positively influence endothelialization, vascular repair, and angiogenesis.

Methods And Results: In mice subjected to sham operation, ovariectomy, or ovariectomy and estrogen replacement treatment, estrogen deficiency significantly decreased EPCs circulating in the peripheral blood and residing in the bone marrow, as well as EPCs that were in vitro expanded from spleen-derived mononuclear cells.