Expression levels of regulatory proteins related to intracellular calcium homeostasis from control (C), diabetes (D), myocardial infarction (I), and diabetes + myocardial infarction (DI) rats (n = 8 for each group). Targeted bands were normalized to cardiac GAPDH. A) Representative blots of SERCA2, Na+-Ca2+ exchanger (NCX) and GAPDH; B) SERCA2; C) NCX; and D) SERCA2/NCX ratio. * p < 0.05 vs. C; † p < 0.05 vs. D; ‡ p < 0.05 vs. I.