Models the adaptation of ATP production by the mitochondria to ATP hydrolysis. This model contains only diffusion, mitochondrial outer membrane (MOM) permeation, and two isoforms of creatine kinase (CK), in cytosol and mitochondrial intermembrane space (IMS), respectively.

Description

  ADENINE NUCLEOTIDE-CREATINE PHOSPHATE MODULE IN METABOLIC SYSTEM EXPLAINS FAST PHASE OF 
  DYNAMIC REGULATION OF OXIDATIVE PHOSPHORYLATION.

  Computational models of a large metabolic system can be assembled from modules
  that represent a biological function emerging from interaction of a small subset 
  of molecules. A “skeleton model” is tested here for a module that regulates the 
  first phase of dynamic adaptation of oxidative phosphorylation (OxPhos) to demand 
  in heart muscle cells. The model contains only diffusion, mitochondrial outer 
  membrane (MOM) permeation, and two isoforms of creatine kinase (CK), in cytosol and 
  mitochondrial intermembrane space (IMS), respectively. The communication with two 
  neighboring modules occurs via stimulation of mitochondrial ATP production by ADP and 
  Pi from the IMS and via time-varying cytosolic ATP hydrolysis during contraction. 

(From vanBeek, 2007)

Figure 2: Model reproduction of figure 2 from vanBeek, 2007 paper. Time course of ATP production by the mitochondria in response to a step in heart rate at time t=0. Top, the pulsatile forcing function, which represents ATP hydrolysis during cardiac systole. Bottom, the response of mitochondrial ATP production.

Equations

The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.