Structural Adaptation and Heterogeneity of Normal and Tumor Microvascular Networks
Figure 7
Functional and structural parameters for mesenteric networks obtained using measured vessel diameters and after simulated adaptation.
Upper panel: oxygen deficit, O2def. Lower panel: variability of cubed diameter at bifurcations, d3var. Three different adaptation modes are shown. The ‘deterministic adaptation’ (second bars from left) uses sensitivity parameters as previously established for mesenteric networks [56] without considering diameter measurement error or biological heterogeneity. Levels for oxygen deficit and structural heterogeneity are lower than those using measured diameters. Inclusion of diameter measurement error brings the parameters close to those obtained with experimentally observed vessel diameters (third bars from left). The further addition of a biological variability in vascular sensitivity to local stimuli and optimization of sensitivity parameters (kh, kc, ks and Ran-ks) allows for a close match of the simulation results to the experimental situation (normal adaptation, right bars). Mean values for three networks are shown with standard deviations.