VEGF distribution during exercise training. The diseased compartment is not included here. Basal VEGF165 secretion rate q = 0.102 molecule/cell/s; clearance rate c
= 0.0206 min-1 ; vascular permeability for VEGF k
= 4 × 10-8 cm/s; VEGFR1 = 10,000, VEGFR2 = 10,000, NRP1 = 10,000 molecules/endothelial cell. Simulation of a 3-hour two-legged knee extension that has been shown to upregulate VEGF mRNA by about 3.5 fold for at least 6 hours . A, Free VEGF concentration in tissue and blood. Six hours after upregulated secretion ceases, the free VEGF concentration returns to baseline. B, Fold increase in free VEGF concentration. The fold increase of VEGF level in the blood is equal to that in the interstitial available fluid. There is a lag of response in the blood compartment.