In Vivo Creatine Kinase Kinetics in Diabetic Heart: Relationship to Cardiac Work.

Adil Bashir¹, Robert J. Gropler¹

In vivo measurements of creatine kinase kinetics provide a better measure of cardiac energy metabolism than PCr to ATP ratio. Using optimized magnetization transfer approach we have measured energy production in rat hearts at two levels of cardiac performance and found it to be closely coupled with work load in normal rat hearts. In diabetic hearts the PCr concentration was lower at rest and the energy production for cardiac work was maintained by higher CK rate constant. When cardiac work was increased the CK flux in diabetic animals did not increase in proportion to the work indicating impaired energy production.