Bond graph simulation of skeletal muscle glucose metabolism.

A mathematical model of skeletal muscle glucose metabolism is presented. This model resulted from the application of thermodynamics combined with the dynamics of an energy storage capability. The physiological system consists of the insulin modulated, carrier-mediated transport of glucose into skeletal muscle, the biochemical reactions of the Embden-Meyerhof pathway, the cyclic 3′,5′ adenosine monophosphate-dependent protein kinase controlled synthesis/degradation of glycogen stores, and the diffusion of lactate from muscle. The metabolic system is defined and synthesized by the construction of the energy flow bond graph.The bond graph model was evaluated by simulating the system response over a 2 min period to step increases in extracellular epinephrine concentration. The simulated response of the metabolites and modulated enzymes corresponds, qualitatively and quantitatively, with in vivo measurements published in the literature.