Figure 2
Network structure of the metabolite interactions in the rods and the RPE considered in our proposed mathematical model. Every node in the network represents the abundance of a specific metabolite. Blue nodes correspond to the metabolites in the RPE, denoted by the subscript E, and purple nodes correspond to the metabolites in the rods, denoted by the subscript r. The orange node represents the extracellular glucose. The enzymatic reactions by which metabolites are used and produced are represented by links: a link \(x\rightarrow y\) indicates that the concentration of metabolite y directly depends on the concentration of metabolite x, in a substrate \(\rightarrow\) product manner. A link \(x {--}\downarrow\) indicates that the corresponding reaction is regulated by a mechanism dependent of metabolite x. The abbreviations used for the metabolites are: [g\(_z\)](t) for glucose inside the cell, [G6P\(_z\)](t) for glucose 6-phosphate, [F16BP\(_z\)](t) for fructose 1,6-bisphosphate, [NADPH\(_z\)](t) for nicotinamide adenine dinucleotide phosphate, [PYR\(_z\)](t) for pyruvate, [LACT\(_z\)](t) for lactate, and [G3P\(_z\)](t) for glyceraldehyde 3-phosphate.
