THE ROLE OF URINARY PROTEINS OF α₁ GLOBULIN FRACTION IN THE FORMATION OF URINARY CALCULI

WITH SPECIAL REFERENCE TO THE AGGREGATING EFFECT OF SERUM α₁ GLOBULIN ON CaCO₃ SUSPENSION

Abstract

It is well known that not only patients with renal disease but healthy individuals also excrete proteins in the urine. However, the role played by urinary protein in the formation of stones is not as yet clearly understood. The present study was undertaken to determine if urinary protein has an action to form a stone and if so what types of protein possess such an action.
Materials and Methods: Normal human serum was separated into fractions by the use of ammonium sulfate and further refractionated with DEAE cellulose. Each of the fractions thus obtained was tested for its stone-forming action by measuring the increase in the sedimentation rate of a suspension of CaCO₃ fine particle and the change in ζ-potential of this suspension that occurred on addition of these fractions. Also, proteins separated by electrophoresis through a cellulose acetate film were identified.
Results: Proteins of γ- and β-globulin fractions were found to exert little aggregating action on CaCO₃ suspension. Most marked aggregation and precipitation of the colloidal substance were observed with proteins of α₁-globulin fraction or with a mixture of α₁-globulin and albumin.
From these findings it was considered that proteins of α₁-globulin fraction or a mixture of proteins of α₁-globulin and albumin in urine are the most likely predominant factor in the formation of stones in urine.