Chronic Phosphocreatine Depletion by the Creatine Analogue β-Guanidinopropionate Is Associated With Increased Mortality and Loss of ATP in Rats After Myocardial Infarction

The failing myocardium is characterized by reductions of phosphocreatine (PCr) and free creatine content and by decreases of energy reserve via creatine kinase (CK), ie, CK reaction velocity (Flux(CK)). It has remained unclear whether these changes contribute directly to contractile dysfunction. In the present study, myocardial PCr stores in a heart failure model were further depleted by feeding of the PCr analogue beta-guanidinopropionate (GP). Functional and metabolic consequences were studied.