Question

3. Consider a growth factor (e.g. VEGF) that is released in the extravascular space such that its concentration Co in the extracellular space is constant and equal to 1 μM. The goal is to deliver the VEGF to the endothelium of a blood vessel passing through this space. The outer radius of the vessel (RO) is 200 μm and the inner radius Ri is 150 μm. The thickness of the endothelial layer is 1 μm. The diffusion coefficient of the VEGF passing through the vessel wall is 1 x 10" cm2/s, while the diffusion coefficient of the VEGF passing through the endothelium is 1 x 10° cm2/s. You may assume that the concentration of VEGF in flowing blood is essentially zero. Find the average concentration of VEGF in the endothelial lining assuming steady-state conditions Basement membrane Endothelial layer (tunica intima) Intercellular cleft

Answer 1

Vascular endothelial growth factor group of proteins are critically regulators of angiogenesis..VEGF important for activation and chemotactic guidance of capillary sprouting..cross section of tissues analysis measurements given here..VEGF Average concentration gradients predicted for steady-state conditions are resting period muscles 10Mm(3%VEGF)..it is adequate for cellular sensing.VEGF concentration gradients are significant,upto 12% change in VEGF concentration over 10Mm in resting muscle..