Physical theory of permeability of vascular walls in relation to atherogenesis 1

The experimental findings hitherto reported on the permeability of serum albumin have been interpreted theoretically. Serum albumin may be transported either by vesicles through the protoplasm of endothelial cells or through intercellular junctions. Based on a new molecular picture of protoplasm and the junction, it is concluded that there exist weak bonds between protein molecules in the system and that a part of the bonds is broken down by mechanical disturbances. This facilitates the transport of serum albumin across the endothelium. Thus it is expected that the permeability is enhanced by wall shear stress, oscillatory flow, stretch and vibration. It is further expected that positive circumferential tension of a blood vessel wall enhances its permeability. This prediction is in good agreement with the experimental finding that hypertensive arterial lesion is apt to develop in those regions where positive circumferential tension is easily induced.