Figure 6.

Selective control mechanisms of the glycolysis, gluconeogenesis and glycogenesis in the insulin-dependent glucose metabolism model. The responses of pAKT, F16P, PEPCK, glycogen and GLC_ex to step (green), pulse (blue) and ramp (red) stimulations of insulin are shown. Glycolysis (F16P) responds to temporal insulin changes (step and pulse stimulations) via FF activation and substrate depletion (orange). Gluconeogenesis (PEPCK) responds to the absolute insulin concentration (step, pulse and ramp stimulations) via FF inhibition (pink). Glycogenesis (glycogen) responds to temporal insulin changes (step and pulse stimulations) via an incoherent feedforward loop (iFFL) (cyan). GLC_ex responds to all insulin stimulations via gluconeogenesis and glycolysis. Note that pAKT-to-pGP connection in the iFFL for the glycogenesis pathway forms a complicated structure by multiple components, such as F16P and PEPCK.