URINARY IONIC CALCIUM AND BINDING-SITES IN NORMOCALCIURIC IDIOPATHIC CALCIUM UROLITHIASIS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 17  (3) , 218-222
Abstract
Total binding sites, ionic Ca and other crystalloids were measured in 41 normocalciuric patients with idiopathic Ca urolithiasis and in 34 normocalciuric healthy subjects. Stoneformers [26] were treated with thiazide to determine the effect of the drug. The average total Ca excretion was higher in patients than in normal subjects; thiazide therapy did not seem to cause a decrease in this fraction in stoneformers. The 24 h excretion of ionic Ca was equal in normal subjects and in patients receiving thiazide therapy, but was higher in patients without therapy. Normal subjects have a significantly higher concentration and total excretion of Mg and citrate. Apparent binding constants for Ca were significantly different for all 3 groups. The concentration of total binding sites was lower in patients with and without therapy than in normal subjects; this was partly attributed to the higher urinary concentration of citrate in normal subjects. Citrate accounted for less than 20% of the total binding sites in urine. There was no significant differential 24 h excretion of binding tests. Measurement of the specific excreting pattern of binding sites on proteins, peptides, nucleotides, and amino acid may emerge with a characteristic pattern in patients with urolithiasis.