STAT3 activity in pressure-overloaded hearts. STAT3 activity in the control rat hearts (control) and pressure-loaded rat hearts (banding) at 2 and 4 weeks after surgery (A). Phosphorylated STAT3 content (p-STAT3) and total STAT3 content (STAT3) in hearts were determined with Western blot analysis. Western blot data for p-STAT3 is normalized by total STAT3 of the same sample, and expressed fold increase compared with mean level of control group (B). 2w: control n=3, banding n=5, 4w: control n=3, banding n=3. Values are reported as means ± SD. *p<0.05 vs. control.