Urinary Calculi Matrices and Urine Polyelectrolytes 1

Summary The amino acid composition of the calculus matrix of various types from different species and the two fractions of urine polyelectrolytes were analyzed by gas chromatography. All matrices and the urine polyelectrolytes had more acidic amino acids than basic amino acids, and, thus, are negatively charged. Nevertheless, there were variations of amino acid compositions between individual calculi and among calculi from different types and species. Apparently, calculus matrix is not composed of preformed compounds. Immunoelectrophoretic tests revealed that part of the calculus matrix was common to the high-molecular-weight urine polyelectrolytes. Because of the readily available carboxyl groups of aspartic acid and glutamic acid in the small-molecular-weight urine poly-electrolytes for cation binding, they could initiate the aggregation of the charged molecules. Therefore, the participation of the aggregated urine polyelectrolytes, including the high-and the low-molecular-weight fractions, in the formation of calculus matrix is feasible.