Profiling of endogenous ligand solutes that bind to serum proteins in sera of patients with uremia.

The profiling of endogenous ligand solutes in sera of patients with uremia was performed by using an ultrafiltration device and high-performance liquid chromatography. Seventeen endogenous ligand solutes, which are ultraviolet-absorbing substances, were detected in a sample volume of 40 microliters, and four ligand solutes were tentatively identified as indoxylsulfate, hippuric acid, 2-hydroxybenzoylglycine, and 3-indoleacetic acid. One of these ligand solutes designated as peak P was thought to be a candidate for a major drug-binding inhibitor in uremia.