Expression of nAChR subunits on subconfluent ECs. (a) FACS analysis demonstrated that the subunits α3, α4, α7, β2, and β4 were expressed on the utilized ECs. Results are shown as box plots displaying 25th and 75th percentiles as boxes and 5th and 95th percentiles as thin lines. n = 4 for each nAChR subunit; *P < 0.01 compared with isotype control. (b) The α7-nAChR was detectable at very low levels on confluent ECs. The expression of α7-nAChR was significantly increased during proliferation (in subconfluent cells), during hypoxia (4 hours), or during stimulation with nicotine (0.1 nM, 12 hours). A representative histogram is shown. GAM/PE, secondary goat anti-mouse antibody labelled with phycoerythrin.