Ussing flux ratio theorems for albumin enhanced fatty acid fluxes across a lipid water interface Original Research Article

A system of transport equations is described for one dimensional diffusion and interaction of ligand and protein in and across the boundaries of four layers. This first two layers are aqueous solutions of ligand, protein and ligand-protein complex, the outer, well stirred and the inner, unstirred. These exchange ligand with two layers of decane-ligand solution. An inner, unstirred decane solution abuts the unstirred aqueous solution and is bounded on the other side by a well stirred decane layer. The system is nonlinear in the coupling, reaction terms and computer solutions for the flux ratio, modelling the Weisiger experiments, show the nonconstant behaviour of this ratio with time that such a nonlinearity might be expected to produce. An alternative, radioisotope experimental approach is suggested and analysed. It gives a linear system of equations for the flux ratio experiments and a flux ratio value of one for all time, even for cases involving parameters with spatial and concentration dependence.