Metabolic Basis of Renal-Stone Disease

URINARY calculi form when the concentration of the crystal-forming substances of which they are composed exceeds solubility. That even this apparent truism generates discussion and requires clarification highlights the state of ferment in the study of metabolic urinary-stone disease. Certainly, crystals precipitate when solubility is exceeded, but since "solubility" in a simple aqueous solution is frequently exceeded in urine without stone formation, the definition of solubility is obviously complex. Solubility is a function of the ionic strength of stone-forming substances, of the salt content of the urine, of the pH of the urine and of the presence of inhibitors of . . .