Effects of high molecular weight solutes on fluid flux across the arterial wall

Abstract

To investigate the mechanisms controlling the flux of plasma proteins into and through the walls of blood vessels, we have studied the effects of two inert protein analogues, Dextran 500 and Poly(ethylene)oxide (PEO) on fluid transport across the walls of intact rabbit common carotid arteries. Transmural fluxes were first measured in vessels pressurized to 150 cmH2O with a solution containing 10 mg/ml albumin alone (control solution) and then with one containing 10 mg/ml albumin plus 10 or 50 mg/ml dextran, or 10 or 30 mg/ml PEO (test solutions). The macromolecule solutions caused a decrease in transmural filtration; the ratios of fluxes with the test solutions to those with the control solutions were 0.89 +/- 0.11 (7), 0.63 +/- 0.08 (8), 0.69 +/- 0.24 (9) and 0.41 +/- 0.09 (4), respectively (Mean +/- SD (n)). These reductions in fluid movement through the vessel wall may be explained quantitatively in terms of the formation of concentration-polarized layers of the macromolecules at the luminal surface or interactions of the macromolecules with the endothelial glycocalyx, causing a decrease in its permeability.

Transport in rat vessel walls. I. Hydraulic conductivities of the aorta, pulmonary artery, and inferior vena cava with intact and denuded endothelia

“…The bathing solution was identical, except for the absence of trypan blue, so as to keep the osmotic pressures on both sides of the wall the same. From its molecular size (19), we estimated the hydrodynamic radius of trypan blue to be ϳ1 nm and, thus, its reflection coefficient to be ϳ0.064 (28), as opposed to albumin's value of 0.8 -1.0 (21,24). Thus the osmotic pressure contribution of the dye was negligible.…”

Location-Dependent Coronary Artery Diffusive and Convective Mass Transport Properties of a Lipophilic Drug Surrogate Measured Using Nonlinear Microscopy

“…These diffusivities are important because they give an indication of the Stokes-Einstein radius ( r ), which is an indication of the ability to diffuse. This is calculated with r = kT/(6πμD) , where k is the Boltzmann constant, T is the absolute temperature, μ is the viscosity, and D is the free (in-solution) diffusivity (41). Substituting the free diffusivities of paclitaxel, sirolimus, and DiI results in Stokes-Einstein radii of similar magnitude (11.2 nm for paxlitaxel, 26 nm for sirolimus, and 58 nm for DiI) (8,16,40).…”