Selective and cell-type specific in vitro responses of endothelial cells to treatment with small-molecule compounds. Twenty-four compounds were tested in vitro on human lymphatic (LECs; black bars) and blood vascular (HUVECs; open bars) endothelial cell cultures for effects on cell proliferation and tube formation. (A) Results of the compound screens using cell proliferation assays. Compounds were screened at a dose of 10 μM in 0.1% DMSO. Control cultures were treated with 0.1% DMSO. (B) Results of the compound screens using tube formation assays. Compounds were screened at a dose of 1 μM in 0.1% DMSO. Control cultures were treated with 0.1% DMSO. 7-Cyclo indicates 7-cyclopentyl-5-(4-phenoxy)phenyl-7H-pyrrolo[2,3-d]pyrimidin-4-ylamine; L-687,384, L-687,384 hydrochloride; Naphthalimide, 4-amino-1,8-naphthalimide; Naphthyridine, 7-chloro-4-hydroxy-2-phenyl-1,8-naphthyridine; Nicardipine, nicardipine hydrochloride; Phenylxanthine, 1,3-diethyl-8-phenylxanthine. Bars represent mean values and SD of 3 independently performed assays.