Heart muscle is both consumer and provider of energy.
In order to address these questions, we have developed small animal models. We have developed a paradigm of control of cardiac function through substrate flux and anaplerosis which is tested both in the laboratory as well as in patients undergoing heart surgery. We are also presently developing a model of rapid quantitative analysis of substrate competition by using positron labeled tracer compounds in conjunction with molecular probes. The availability of cDNA probes for the key enzymes of glucose metabolism will permit a coordinated analysis from transcription to protein expression and changes in metabolic flux. We have identified major switches of metabolic enzymes in heart muscle undergoing functional recovery with mechanical unloading.