(A) Cardiomyocytes were exposed to ET-1 (5 min) in the presence of indicated concentrations of BI-D1870. Samples were immunoblotted for phospho-GSK3α/β, phospho-ERK1/2 or total ERK1/2. The experiment was repeated with similar results. (B) Cardiomyocytes were exposed to 10 μM BI-D1870 for the times indicated or ET-1 (5 min). Samples were immunoblotted for phospho- or total ERK1/2. The experiment was repeated with similar results. (C) Cardiomyocytes were unstimulated (control), or exposed to PD184352 or BI-D1870 (70 min). RNA expression was determined using Affymetrix rat exon 1.0 ST arrays. RNAs regulated by PD184352 and/or BI-D1870 alone were clustered according to inhibition or enhancement. Mean expression (n=3) relative to the controls is shown for each RNA (numbers in each cluster are indicated). (D, F and H) Cardiomyocytes were unstimulated (control), exposed to PD184352, BI-D1870 or ET-1 alone (1 h), or exposed to ET-1 in the presence of PD184352 or BI-D1870. RNA expression was determined using Affymetrix rat exon 1.0 ST arrays. RNAs up-regulated by ET-1 were clustered according to effects of each inhibitor (numbers in each cluster are shown). Results are means±S.E.M. for RNAs in each cluster relative to controls. *P<0.001 and **P<0.01 relative to the control; †P<0.001 relative to ET-1. (E, G and I) Cardiomyocytes were exposed to ET-1 in the absence/presence of PD184352 or BI-D1870 and mRNA expression for selected transcripts analysed by qPCR. Results are means±S.E.M. (n=4).