燐酸塩尿の出現における尿pHの役割

Abstract

The density of calcium phosphate and the pH were determined in 15 postprandial urine specimens with heavy precipitation of amorphous calcium phosphate, that is phosphaturia, collected from 5 patients with calcium urolithiasis (stone-formers) and 3 patients with no known urological disease (controls). Phosphaturia, not related to urinary tract infection or administration of alkalinizing agents, was found repeatedly at our outpatient clinic in these patients. The correlative relationship was not confirmed between the density of calcium phosphate and the pH. The concentration of calcium and phosphorus was also determined in 10 urine specimens with phosphaturia. The concentration of phosphorus was correlated significantly with the pH (r = -0.775, p less than 0.01), although the concentration of calcium was not correlated with the pH. The pH of 11 urine specimens with phosphaturia from the controls was 7.51 +/- 0.31 (mean +/- S.D.) and the pH of 18 urine specimens with phosphaturia from the stone-formers was 6.81 +/- 0.34. The pH was significantly lower in the urine specimens from the stone-formers than in those from the controls (p less than 0.01). We have noted that the occurrence of phosphaturia depends not only on the urinary pH but on the concentration of phosphorus. It is interesting that phosphaturia often occurs in urine specimens with a pH below 7 in stone-formers.