A) Heart weight, HW (left panel), and Lung weight, LW (right panel), were measured at 4 weeks after surgery and normalized to tibia length (TL). Isoproterenol challenge had no effects on either HW/TL or LW/TL in sham-operated animals (SHAMi vs. SHAM). Pressure overload with daily isoproterenol challenge (ACi) induced cardiac hypertrophy and lung congestion, and CGP-37157 treatment attenuated both cardiac hypertrophy and lung congestion (ACi+CGP). B) Interstitial fibrosis was analyzed with Masson’s Trichrome staining. Left panel: representative images from each experimental group; right panel: measurements of interstitial fibrous tissue showing that pressure overload, together with isoproterenol challenge, induced significant fibrosis in ACi group, which was attenuated by CGP-37157 treatment (ACi+CGP). C) Cardiac function is preserved by CGP-37157. Upper panel: representative pictures of echocardiographic study; lower panel: measurements of fractional shortening (FS) (left) and diastolic LV internal dimension (LVIDd) (right) showing reduced FS and LV dilation in ACi group but not in CGP-37157 treated group. D) Left panel: representative LV pressure-volume loops. Heart from ACi group shows increased end-diastolic volume and depressed end-systolic pressure-volume relation. Right panel: summary data of end-systolic LV pressure (upper panel) and dP/dt_ip (dP/dt normalized to pressure) (lower panel). Isoproterenol treatment in the absence of aortic constriction (SHAMi) had no effect on cardiac function.