Gender and vascular reactivity

Estrogen receptors are found on vascular endothelial and smooth muscle cells; their expression is influenced by exposure to the hormone. Estrogen receptors influence non-genomic events, which are rapid in onset and genomic events, which are longer acting responses. Estrogens affect vascular tone indirectly by modulating release of endothelium-derived vasoactive factors and directly by modulating intracellular calcium in vascular smooth muscle cells. Estrogens indirectly affect thrombotic events and inflammation by altering platelet aggregation and leukocyte adherence and migration, respectively. Estrogens also influence production of mitogens which, when released at sites of vascular injury, affect vascular remodeling. Although estrogens initiate vascular responses, genomic sex may influence and/or limit expression of estrogen receptors and therefore actions of sex steroid hormones throughout the vasculature.