A compartment model of VEGF distribution in blood, healthy and diseased tissues

BMC Systems Biology

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/μ g protein	3.4–6.9	pmol/cm³ tissue
*VEGFR1 tissue concentration*
Human vastus lateralis, rest	1.6–1.8	pg/μ g 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/μ g 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	μ M	46	pmol/cm³ tissue
Vessel BM	13	μ M	1	pmol/cm³ tissue
Myocyte BM	13	μ M	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 μ m². 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].

ISSN: 1752-0509