Figure 4.
Chronic administration of isoproterenol (ISO) induces excessive hypertrophy in Stat3cKO hearts. A, Echocardiographic analysis of cardiac function of control and Stat3cKO mouse (2-month old) in response to chronic ISO treatment. Left panel shows fractional shortening (FS%); Right panel shows ejection fraction (EF%) (Control: N = 10; Stat3cKO: N = 7), *P<0.05, **P<0.01. B, Upper panel shows representative images of control and Stat3cKO hearts (2-month old) prior to and after 7-day ISO perfusion. Lower panel shows heart weight vs tibia length ratios (N = 7/each group) of Stat3cKO hearts compared to controls after 7-day ISO perfusion, *P<0.05, **P<0.01. C, Upper panel shows representative fluorescent images of WGA (wheat germ agglutinin) staining (in green) of comparable left ventricular region of control and Stat3cKO hearts prior to and after 7-day ISO perfusion; DAPI, in blue. Lower panel shows the quantitation of cardiomyocyte transverse area (in μ2) of Stat3cKO and control hearts after 7-day ISO perfusion (N = 5/each group), *P<0.05, **P<0.01.