Heart failure type-specific decrease in cTnI phosphorylation. (A) Phosphorylation levels in left ventricular samples were determined by Phos-tag SDS-PAGE, followed by a Western blot against cTnI (top). Unphosphorylated cTnI (indicated by 0P, where human cTnI weighs 24,008 D) migrates faster than single (1P) or doubly (2P) phosphorylated cTnI. Unphosphorylated recombinant troponin (cTn, left lane) was used as a negative control, and each lane represents a single cardiac sample from a donor or patient. (B) Densitometry analysis for each lane in A was used to calculate the level of cTnI phosphorylation. A single measurement was made for each of the 7 donor hearts and 10 hearts from each heart failure group, indicated in Tables 1 and 2. Source data are available for this figure: SourceData F5.