Fig 9. PKA blockade prevents contractility reduction induced by NOS-1 inhibition.

Accumulative concentration-response curves of heart contractility (dP/dt)max to isoproterenol prior (Control) or after adding PKA inhibitor H89 0.5μM (A); or H89 0.5μM plus NOS-1 inhibitor SMTC 300nM (B). The same data are expressed in absolute values (Left) or as relative values, corrected by the corresponding contractility values after treatment with inhibitors (Right). (* p<0.01 vs. Control, paired t test). Best fit parameters could not be calculated because 1μM isoproterenol was not tested (lack of saturation).