[Inhibitory effect of sodium pentosan polysulfate on the formation, growth and aggregation of calcium oxalate in vitro].

The inhibitory effects of sodium pentosan polysulfate (SPP) on the formation, growth and aggregation of calcium oxalate (CaOx) crystals were estimated by means of a Coulter counter TA II by the seed crystal method, whole urine method and infrared spectroscopic method. In the seeded crystal system, the inhibitory activities on aggregation (Ia), growth (Ig) and size (Is) were calculated from the change of the number, volume and diameter of crystals. At above 0.5 microgram/ml, SPP inhibited the aggregation and growth of added CaOx monohydrate (COM) and dihydrate (COD) crystals. In the whole urine system, after determining the metastable limit, the formation and growth of CaOx crystals precipitated in response to a load of sodium oxalate was measured. SPP had a strong inhibitory effect on the formation and growth in the concentration of over 5 micrograms/ml. In infrared spectroscopic study, the ratio of COD/COM formed in whole urine increased with the concentration of SPP. SPP therefore might have prevented the recurrence of stone formation.