17-BETA-ESTRADIOL STIMULATION OF ENDOTHELIAL K+ CHANNELS

Whole-cell membrane current recordings under voltage clamp were made f rom freshly isolated rabbit aortic endothelial cells. Intracellular Ca 2+ signals of fura-2 loaded both native single aortic endothelial cell s and intact endothelium from rabbit cardiac valves were measured usin g imaging fluorescence microscopy. Application of 17-beta-estradiol st imulated rapid discharge of transient outward currents and induced an increase in the intracellular free Ca2+ concentration ([Ca2+](i). The stimulated discharge of outward currents and [Ca2+](i) were reduced by extracellulary applied tetraethylammonium (TEA). (C) 1995 Academic Pr ess, Inc.