Analysis of urinary concentrations of calcium phosphate crystal-associated proteins: alpha2-HS-glycoprotein, prothrombin F1, and osteopontin.
It has been reported that prothrombin F1 and osteopontin (OPN) have strong inhibitory effects on calcium oxalate crystallization and are produced in stone-forming kidneys in animal models. It is important to evaluate urinary concentrations of these proteins for patients with renal stones and healthy control subjects. Urinary macromolecules were collected from nine healthy individuals, nine stone-formers, and five patients with primary hyperparathyroidism (HPT). Each 50-mg aliquot of urinary macromolecules was mixed with calcium phosphate solution, and calcium phosphate crystal-precipitated proteins (alpha2-HS-glycoprotein, prothrombin F1, and OPN) were obtained. The proteins were analyzed by anion-exchange chromatography. Furthermore, OPN levels in whole urine from 18 healthy individuals, 31 stone-formers, and two patients with HPT were measured using a new enzyme immunoassay system. The elution peaks for prothrombin and OPN were significantly smaller for the stone-formers and patients with HPT, compared with the healthy control subjects. Urinary concentrations of OPN assessed using the enzyme-linked immunosorbant assay were significantly lower for stone-formers. Lower urinary excretion of prothrombin F1 and OPN by stone-formers might be one of the reasons for stone formation.
Nishio
S
S
Department of Urology, Ehime University, School of Medicine, Japan. nishio@m.ehime-u.ac.jp
Hatanaka
M
M
Takeda
H
H
Iseda
T
T
Iwata
H
H
Yokoyama
M
M
D000328:Adult; D001798:Blood Proteins / Q000652:urine*; D002130:Calcium Phosphates / Q000652:urine*; D003460:Crystallization; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053495:Osteopontin; D011516:Prothrombin / Q000652:urine*; D012795:Sialoglycoproteins / Q000652:urine*; D014545:Urinary Calculi / Q000209:etiology; D060749:alpha-2-HS-Glycoprotein
C556354:AHSG protein, human; D001798:Blood Proteins; D002130:Calcium Phosphates; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D060749:alpha-2-HS-Glycoprotein; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D053495:Osteopontin; C485838:calcium phosphate, monobasic, anhydrous; D011516:Prothrombin; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous