In vitro activity: Nebivolol shows high affinity and selectivity for beta 1-adrenergic receptor sites in a rabbit lung membrane preparation (Ki value = 0.9 nM and beta 2/beta 1 ratio = 50). Nebivolol displays β1-adrenoceptor selectivity with the Ki(β2)/Ki(β1) value of 40.7 judged by competition experiments to 3H-CGP 12.1777 in the presence of CGP 207.12 A (300 nM, Kiβ2) or ICI 118.551 (50 nM, Kiβ1). Nebivolol reduces cell proliferation of human coronary smooth muscle cells (haCSMCs) and endothelial cells (haECs) in a concentration- and time-dependent maner. Nebivolol treatment for 7 days causes significant reduction in cell growth of haCSMCs with IC50 of 6.1 μM, and inhibits accelerated haCSMC proliferation stimulated by growth factors PDGF-BB, bFGF, and TGFβ with IC50 values of 6.8 μM, 6.4 μM and 7.7 μM, repectively. Nebivolol treatment (10-5 M) of haCSMCs for 48 hours induces a moderate apoptosis of 23% and a decrease from 16% to 5% in the number of cells in S-phase. During Nebivolol incubation, NO formation of HaCEs increases, while endothelin-1 transcription and secretion are suppressed.

Cell Assay: Cells [Human coronary smooth muscle cells (haCSMCs) and endothelial cells (haECs)] are exposed to different concentrations of Nebivolol (10-7~10-5 M) for 1, 2, 4, 7 and 14 days. Cell proliferation is analyzed by bromodeoxyuridine (BrdU) incorporation, and cell apoptosis is detected by PI or annexin V staining.

Mol Pharmacol. 1988 Dec;34(6):843-51; Circ J. 2008 Apr;72(4):660-70.