Fig. 6.

APAU treatment mitigates the reduction in sarco(endo)plasmic reticulum Ca²⁺-ATPase (SERCA) expression and the increase in brain natriuretic peptide (BNP) level in hearts from UCD-T2DM rats. A and B: at the time that APAU treatment was started (time 0 in Fig. 1), SERCA (A) and BNP (B) levels in hearts from UCD-T2DM rats [prediabetic (PD)] were similar to those in hearts from control Sprague-Dawley rats. C and D: SERCA expression was significantly reduced, whereas the BNP level was increased, in hearts from both treated and untreated diabetic UCD-T2DM rats versus nondiabetic control rats. However, APAU treatment alleviated both SERCA downregulation and the increase in BNP expression. Phospholamban (PLB) expression was unchanged, but more PLB was phosphorylated at Ser¹⁶ (PLB-S16) in the untreated group. Na⁺/Ca²⁺ exchanger (NCX) was significantly elevated in the APAU-treated group. C: representative examples; D: mean data. Western blots were run at least 4 times, and equal loading was verified with GAPDH. Measurements were done at the end of the 6-wk treatment period. *P < 0.05; **P < 0.01; ***P < 0.001.