Fig. 6.
Isoproterenol challenge in ex vivo heart after 3 wk of diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet in caveolin-3 (Cav-3) overexpression (OE) and transgene negative (TGneg) mice. Langendorff perfusion with incremental concentrations (100 pM, 1 nM, 10 nM, 30 nM, 100 nM, 300 nM, and 1 µM) of isoproterenol were performed (n = 7–10 per group). At 30–300 nM of isoproterenol, DDC-fed TGneg hearts showed significant less contractility (dPmax/dt) and relaxation (dPmin/dt) compared with chow-fed TGneg hearts, but no significant difference existed between DDC-fed Cav-3 OE hearts and chow-fed TGneg hearts. HR, heart rate; LVDP, left ventricular developed pressure (difference between LV systolic and diastolic pressure). *P < 0.05, **P < 0.01 compared with chow-fed TGneg mice. ††P < 0.01 compared with chow-fed Cav-3 OE mice.