Calcium homeostasis behavior and cardiac function on left ventricular remodeling by pressure overload

Figure 1. Relationship between muscle length variation, in % of maximum length (Lmax), and resting tension (RT). P<0.01, Sham vs aortic stenosis (AoS) (non-linear regression model adjustment using the least squares method).

Figure 2. Relationship between muscle length variation, in % of maximum length (Lmax), and developed tension (DT). AoS: aortic stenosis.

Figure 3. Percent calcium elevation from baseline (Ca2+ concentration: 0.5 mM). DT: maximum developed tension; +dT/dt: maximum rate of tension development; -dT/dt: maximum rate of tension decline. Sham: animals submitted to simulated surgery (n=10); AoS: animals submitted to aortic stenosis surgery (n=10). Data are reported as median, maximum, and minimum (A and C), or means±SD (B). *P<0.05, Sham vs AoS [analysis of variance for repeated measures and Bonferroni post hoc test (bar chart) or Kruskall Wallis and Wilcoxon tests complemented by Dunn post hoc test (box plot)].

Figure 4. Percent of post-rest contraction from baseline (Ca2+ concentration: 0.5 mM). DT: maximum developed tension; +dT/dt: maximum rate of tension development; -dT/dt: maximum rate of tension decline. Sham: animals submitted to simulated surgery (n=10); AoS: animals submitted to aortic stenosis surgery (n=10). Data are reported as median, maximum, and minimum. P<0.05, Sham vs AoS (Kruskall Wallis and Wilcoxon tests complemented by Dunn post hoc test). Different letters indicate statistical difference among the moments within each group.

Figure 5. Function recovery in percentage post cyclopiazonic acid (CPA). DT: maximum developed tension; +dT/dt: maximum rate of tension development; -dT/dt: maximum rate of tension decline. Sham: animals submitted to simulated surgery (n=10); AoS: animals submitted to aortic stenosis surgery (n=10). Data are reported as means±SD. *P<0.05, AoS vs Sham (analysis of variance for repeated measures and Bonferroni post hoc test). Different letters indicate statistical difference among the moments within each group.

Figure 6. Western blot analysis of intracellular Ca2+-cycling proteins in myocardium from Sham and aortic stenosis (AoS) rats (n=6 in each group). A, Representative bands of the proteins. Quantification of myocardial (B) L-Type Ca2+ channel, (C) ryanodine receptor (RyR), (D) Na+/Ca2+ exchanger (NCX1), (E) sarcoplasmic reticulum calcium-ATPase (SERCA2a), (F) total phospholamban (PLB), (G) phosphorylated PLB on serine-16 (pPLB Ser16), and (H) phosphorylated PLB on threonine-17 (pPLB Thr17) normalized to glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Quantification of (I) SERCA2a, (J) pPLB Ser16, and (K) pPLB Thr17 normalized to total PLB. Data are reported as means±SD. P<0.05, Student's t-test.