STUDIES ON CALCIUM-OXALATE MONOHYDRATE CRYSTALLIZATION - INFLUENCE OFINHIBITORS

A simple model to study calcium oxalate mononydrate (COM) crystallizat ion on different substrates is presented and the action of different p otential inhibitors is evaluated and discussed. COM heterogeneous nucl eation was assayed on solid surfaces as calcium phosphate, mixtures of mucin with calcium phosphate, and wax. In the presence of a non-prote cted non-renewed solid surface in contact with normal urine, COM cryst al formation could be detected at short intervals (3 h). The most acti ve heterogeneous nucleation capacity corresponded to calcium phosphate . In the presence of 10% mucin, owing to the renewal of the surface la yer no COM crystal were detected on the pellet's surface. The study of citrate and pentosan polysulphate (a semisynthetic polysaccharide) on COM heterogeneous nucleation demonstrated some important inhibitory e ffects when concentration increased and time decreased. Maximum effect s were selectively manifested on calcium phosphate surfaces. Only phyt ic acid at adequate concentration exhibited a total inhibitory capacit y of COM formation, even during longer intervals (15 h).