Proteins and Other Biocolloids of Urine in Health and in Calculous Disease. I. Electrophoretic Studies at pH 4.5 and 8.6 of Those Components Soluble in Molar Sodium Chloride1

Abstract

The biocolloids were recovered from the urine of normal subjects, from patients with calculous disease, and from patients with pyelonephritis, nephrosis or lupus erythematosus, by ultra-filtration and pressure dialysis. The lyophilized dry weights of the total 24 hour residues are quite constant for normal subjects, averaging 90 mg/24 hours, of which, 42-52 mg are soluble in [image]-NaCL The portion which is insoluble in [image] NaCl is a single mucoprotein (uromucoid), derived from the secretory epithelium of the urinary tract. Biocolloids which are soluble in [image] NaCl were studied electrophoretically in buffers of pH 8. 6 and 4. 5. The major protein components of human serum are also present in normal urine. The A/G ratio of the normal urinary proteins is reversed from that of normal serum due to the presence of glycoproteins. These glycoproteins have the same electrophoretic mobilities as the glycoproteins (MP-2) of normal serum at both pH 4. 5 and at pH 8. 6, where they migrate with the alpha globulins. On the other hand, orosomucoid (MP-1) is present in normal urine in extremely minute concentrations. Patients with calcigerous renal calculi were found to have a marked increase in the total 24 hour excretion of biocolloids. Epithelial secretions (uromucoid), albumin, and mucoproteins not present in normal urine, accounted for this increase. The abnormal mucoproteins of calculous disease urine were iso-electric at pH 4. 5 and their electrophoretic mobility was less than the alpha-1 globulins of serum at pH 8. 6. These mucoproteins were found in greatest concentration in the urine of three patients with hyperparathyroidism.