Table 3

VEGF concentration and receptor densities for the healthy tissue (human vastus lateralis)


Measured parameter
Tissue model

Value
Unit
Value
Unit

Free VEGF concentration
Human vastus lateralis, rest
1
pM
6.2 10-5
pmol/cm3 tissue

Total VEGF tissue concentration
Human vastus lateralis, rest
1–2
pg/μg protein
3.4–6.9
pmol/cm3 tissue

VEGFR1 tissue concentration
Human vastus lateralis, rest
1.6–1.8
pg/μg protein
1.1–1.2
pmol/cm3 tissue



60,000–68,000
#/EC

VEGFR2 tissue concentration
Human vastus lateralis, rest
0.33–0.5
pg/μg protein
0.24–0.34
pmol/cm3 tissue



13,000–19,000
#/EC

NRP1 tissue concentration



0.018–1.8
pmol/cm3 tissue



1,000–100,000
#/EC

ECM binding site density
ECM
0.75
μM
46
pmol/cm3 tissue
Vessel BM
13
μM
1
pmol/cm3 tissue
Myocyte BM
13
μM
4
pmol/cm3 tissue

The conversion of receptor densities to tissue concentrations is based on the relationship mentioned in table 2, and the surface area of an endothelial cell, 1000 μm2. VEGF concentration is normalized based on the entire interstitial space, since it diffuses throughout: 6.2 107 (pmol/cm3 tissue)/M (here, M = moles/liter interstitial space). VEGF binding sites in the ECM and BMs are based on those volumes: 6.2 107 (pmol/cm3 tissue)/M(ECM), 5.7 104 (pmol/cm3 tissue)/M(EBM), 3.1 105 (pmol/cm3 tissue)/M (MBM). For example, M(EBM) = moles/liter endothelial basement membrane. Conversions from pg/mg protein are based on 155 mg protein/g of tissue and 45 kDa VEGF, 210 kDa VEGFR1, 240 kDa VEGFR2 [6].

Stefanini et al. BMC Systems Biology 2008 2:77   doi:10.1186/1752-0509-2-77