(A–D) Cardiomyocytes were exposed to A61603 for the times indicated and mRNA expression was measured by qPCR. Results expressed relative to controls are means±S.E.M. for four independent experiments. Expression profiles are grouped according to temporal regulation. (E–G) Adult rat hearts were perfused retrogradely under control conditions (white bars), with A61603 alone (black bars) or with A61603 in the presence of PD184352 (grey bars). (E) mRNAs significantly up-regulated by A61603 with significant inhibition by PD184352. (F) mRNAs significantly up-regulated by A61603 without significant inhibition by PD184352. (G) mRNAs not significantly up-regulated by A61603. Results are means±S.E.M. for at least four hearts per condition. *P<0.001, **P<0.01 and @P<0.05 relative to control; #P<0.001, †P< 0.01 and ‡P<0.05 relative to A61603 alone.