URINARY LOW MOLECULAR PROMOTER OF CALCIUM OXALATE MONOHYDRATE CRYSTAL AGGREGATION

PRELIMINARY REPORT

Abstract

Urinary low molecular fractions (less than 10, 000mol. wt.) were obtained by gel filtration chromatography of urinary nondialyzable materials from a male calcium oxalate containing stone former. It was found that the low molecular fractions promoted the aggregation of calcium oxalate seed crystals and resulted in the formation of small spherical bodies of the crystals. The volume-size distributions of the crystals were also measured to ascertain the aggregating activity of the fractions by means of Coulter counter method. The aggregating activity of the low molecular fractions to the crystals was decreased in the presence of urinary high molecular fractions which were fractionated from the same urinary nondialyzable materials and had an inhibitory activity of calcium oxalate crystal growth. It is supposed that the low molecular promoter is an uronic acid-rich glycoprotein, because the fractions having aggregating activity had high contents of uronic acid.