Molecular and cellular biochemistry
-
Mol. Cell. Biochem. · Jan 2006
Reduced sarcoplasmic reticulum Ca2+ -ATPase activity and dephosphorylated phospholamban contribute to contractile dysfunction in human hibernating myocardium.
Human hibernating myocardium (HHM) is characterized by reversible contractile dysfunction during chronic ischemia. A disturbed calcium-homeostasis is a decisive factor for reduced functional capacity in heart diseases. We therefore investigated calcium-handling proteins in HHM. ⋯ RyR2 and NCX showed no significant alteration. In HHM a decreased activity of SERCA2a due to an impaired phosphorylation of PLN contributes to contractile dysfunction. The increase in the relative ratio of PLN/SERCA2a leads to a decreased calcium affinity of SERCA2a.