Table 4 Model Conditions
Parameter | Symbol | Value | Ref. |
|---|---|---|---|
Initial mean VEGF level | V0 | 1 pM | [67] |
VEGF gradient over domain | g0 | 5%/40 μm | Assumed |
[HSPG] in ECM | [H] Total | 0.75 ·10-6 mol/L | [41] |
System with receptors | Â | Â | Â |
   Total VEGFR2 levels per area of tip cell on vasculature | [R2]Total | 10,000/(area of tip cell); area of tip cell = 515 μm2 | [42] |
   Total VEGFR1 levels per area of tip cell on vasculature | [R1]Total | 10,000/(area of tip cell) | Assumed |
   Total NRP1 levels per area of tip cell on vasculature | [N1]Total | 30,000/(area of tip cell) | Assumed |
   VEGF (typically VEGF165) secretion rate | q | 5.27·10-5 molec/μm2 ·s | Calculated |
   VEGF clearance rate | kclear | 0.0399 μm/s | Calculated |
System without receptors | Â | Â | Â |
   VEGF (typically VEGF165) secretion rate | q | 4.39·10-5 molec/μm2·s | Calculated |
   VEGF clearance rate | kclear | 0.0948 μm/s | Calculated |
HSPG gradient (Figure 4B) | Â | Â | Â |
   HSPG gradient | gH0 | 30%/40 μm | Assumed |
Soluble VEGF degradation (Figure 4C) | Â | Â | Â |
   Degradation rate of soluble VEGF | kdegV | 0.001 s-1 | Assumed |
   Degradation rate of matrix-bound VEGF | kdegVH | 0 s-1 | Assumed |
Matrix-sequestered VEGF degradation scheme (Figure 4D) | Â | Â | Â |
   Degradation rate of soluble VEGF | kdegV | 0.001 s-1 | Assumed |
   Degradation rate of matrix-bound VEGF | kdegVH | 0.001 s-1 | Assumed |