Figure 7.
Effect of Rho kinase and MLCK inhibition on Sph-1-P–mediated changes in TER. (a) Confluent bovine pulmonary artery endothelium grown on gold microelectrodes were pretreated with either vehicle control, Rho kinase inhibitor, Y27632 (10 μM), or the MLCK inhibitor, ML-7 (20 μM) for 60 minutes, followed by stimulation with Sph-1-P (1 μM) or thrombin (Thr, 100 nM). The maximal Sph-1-P–induced endothelial barrier enhancement observed at 10–15 minutes was attenuated by the reduction of Rho kinase activity, but not affected by the inhibition of MLCK activity, whereas maximal thrombin-induced endothelial barrier disruption (30 minutes) was significantly blocked by both Rho kinase and MLCK inhibition. Data are mean ± SE, n = 3, P < 0.05.