Facilitated dissociation of albumin-fatty acid complexes by rat hepatocytes.

Experiments were conducted comparing palmitate clearance by hepatocyte monolayers, polyethylene and that predicted by the diffusion-reaction model. The objective was to learn whether the albumin-dependent enhancement of unbound palmitate clearance was wholly attributable to codiffusion of bound and unbound fatty acid across an unstirred fluid layer, or whether the uptake flux was also contributed by facilitated dissociation of albumin-fatty acid complexes at the cell surface. We use a model-independent formulation of the facilitation phenomenon to explore this question at low concentrations of albumin. The central finding that facilitation occurs takes into consideration albumin-dependent changes in solution viscosity, endogenous albumin secretion and the adsorption of albumin to the polyethylene surface.