Binding of reserpine to plasma albumin and lipoproteins

The binding of reserpine to plasma albumin and lipoproteins was studied by equilibrium gel filtration. Reserpine was shown to be over 96 per cent bound to plasma proteins. Two discrete peaks of plasma-protein binding were identified, the one in the lipoprotein fraction and the other corresponding to plasma albumin. Binding to the lipoproteins showed large variations between normal subjects (mean extent of binding of 5.4 ± 0.8) and hyperlipoproteinemic patients (mean of 11.2 ± 0.9), and correlated very significantly with the triglycéride and total lipid concentration and, to a lesser extent, with the concentration of cholesterol in the plasma. It is concluded that plasma lipoproteins, as well as albumin, bind reserpine, and that the degree of lipoproteinemia may contribute to variations in plasma-drug binding.