[Correlations between the metastable solutions of calculus-forming salts and crystals from coexistent insoluble...

The correlations between the individual stone-forming systems, expecially the induction of heterogeneous crystallization from metastable solutions of one stone-forming system by preformed crystals of the other stone-forming system, were measured semiquantitatively by the Coulter-Counter-Size Distribution Analyzer technique. It has been found out that Ca-oxalate crystals may represent potent triggers and accelerators of the phosphate precipitation from metastable Ca-phosphate solutions. The importance of this phenomenon could be attributed especially to the induction of crystal rich phosphate crystalluria at moderate pH values (6,5--6,8) by the preceding Ca-oxalate crystalluria (,,starter "resp." primer "crystalluria). The favouring, promoting influence of uric acid on the stone formation and growth of Ca-oxalate crystals could be observed with the same experiments under changed conditions. This mechanism could be of some importance in the case when Ca-oxalate precipitates from the urine, saturated by uric acid, at low pH values (5,0--6,0). Uric acid resp. sodium urate crystals showed a moderate by clear favouring effect on the formation of Ca-phosphate crystals from metastable solutions. The influence of Ca-phosphate crystals upon the growth of Ca-oxalate crystals proved to be very limited.