Effect of nAChR inhibition on angiogenesis in vitro. (a) Seeding of ECs on Matrigel resulted in capillary network formation within 48 hours. (b–d) Mecamylamine dose-dependently inhibited network formation: 1 nM (b), 100 nM (c), and 1 μM (d). (e) If mecamylamine (1 μM) was removed after 36 hours, the effect of mecamylamine on in vitro angiogenesis was reversible and endothelial networks had formed by 72 hours. Representative microscopic pictures are shown. (f) This effect of mecamylamine on network formation was mimicked by the α7-nAChR inhibitor α-bungarotoxin (1 nM). (g) Other selective nAChR antagonists did not result in a significant reduction of network formation. Results are shown as box plots displaying 25th and 75th percentiles as boxes and 5th and 95th percentiles as thin lines (n = 4; *P < 0.001 vs. control. Data are expressed as a percentage of network formation under control conditions, i.e., in the presence of vehicle alone.