Women are less susceptible than men to cardiovascular disease and atherosclerosis as long as their blood estrogen levels are elevated. Valverde et al. show that estrogens can directly bind to a subunit of the maxi-K channel. These calcium-regulated potassium channels are key regulators of vascular smooth muscle cells, which constrict arteries and raise blood pressure. This acute estrogen effect does not require genome activation or generation of other intracellular signals.
Valverde, M.A., Rojas, P., Amigo, J., Cosmelli, D., Orio, P., Bahamonde, M.I., Mann, G.E., Vergara, C., Latorre, R. (1999) Acute activation of maxi-K channels (hSlo) by estradiol binding to the β subunit. Science 285: 1929-1931. [Abstract] [Full Text]