Fig 3. Selective downregulation of SR Ca²⁺ handling proteins and decreased SR Ca²⁺ uptake in TG mice hearts.

Equal amounts of total protein prepared from the atrial (A) and ventricular (C) tissues of one-month old TG and NTG mice were separated on SDS-PAGE and immunoprobed with specific antibodies. Quantitation of signals by densitometry and normalization to GADPH levels shows selective downregulation of SR Ca²⁺ handling proteins in the TG mice atria (B) and ventricles (D). *indicates the significant difference (p<0.05) between NTG and TG groups. n = 5. Calcium dependent SR Ca²⁺ uptake is significantly decreased in atria (E) and in the ventricles (F) of one-month old TG mice. For each atrial Ca²⁺ uptake experiment, atria from four mice were pooled. n = 4 for each group. The V_max of Ca²⁺ uptake was obtained at pCa 5.5.