Effect of BK and desArg9BK on [3H]thymidine uptake in rabbit smooth muscle cells. (A) Rabbit smooth muscle cells were treated with BK, desArg⁹BK, PDGF, or buffer alone (control) for 24 hours and then assayed for [³H]thymidine incorporation as described in “Materials and methods.” The results are presented as percent of basal, where 100% basal is the amount of radioactivity in control. (B) Cells were incubated with BK or desArg⁹BK in the absence and presence of desArg⁹[Leu⁸]BK (DLBK) (B1 receptor antagonist) or HOE140 (B2 receptor antagonist). [³H]Thymidine incorporation was measured after 24 hours. Results are expressed as percent of control, where 100% control is the incorporation in the presence of BK or desArg⁹BK. The results represent mean ± SEM of at least 3 independent experiments done in triplicate. *P < .05 and **P < .01 compared with the control value as determined by Student t test. (C) Rabbit smooth muscle cells were treated for 24 hours with BK (1 μM) in the presence or absence of carboxypeptidase inhibitors of the kininase I type (DL-2-mercaptomethyl-3-guanidinoethylthiopropionic acid [MGTPA], potato carboxypeptidase inhibitor [PCI], 2-guani-dinoethylmercaptosuccinic acid [GEMSA], ϵ-aminocaproic acid [EACA], or a mix of all inhibitors; black bars). All inhibitors were applied at a final concentration of 10 μM. Control samples in the absence of BK were run in parallel (white bars). The results are presented in percent of thymidine incorporation into the DNA of the rabbit smooth muscle cells, where the incorporation into nontreated cells was set to 100%. The graph represents the mean ± SEM of 2 independent experiments performed in triplicate.