Study of inhibitor and nucleator activities in calcium stone formers.

In 30 calcium stone formers urinary citrate, magnesium, calcium, phosphorus, uric acid and oxalate excretion were compared with the activity product ratios and formation product ratios of oxalate, brushite and monosodium urate. A positive correlation was found between calcium and phosphorus excretions and APRox and APRbr; no correlation was found between oxalate, uric acid, citrate and magnesium excretion and APR or FPR. Thus calcium and phosphorus contribute significantly to the increments of urine saturation; citrate and magnesium do not modify the inhibitor urinary activity, and oxalate and uric acid do not influence inhibition and saturation activities of urine.