糖尿病性腎症における運動負荷時の尿中シアル酸合有糖蛋白分子量パターン

Abstract

Urinary glycoprotein patterns after exercise were studied by electrophoresis in patients with diabetes mellitus for early diagnosis of diabetic nephropathy. The subjects were 21 patients with non-insulin dependent diabetes mellitus and 5 healthy volunteers. For each subject, voiding urine collection was done at rest and after a 20-minute exercise (300 Kpm/min). Urine samples were freeze-dried and subjected to electrophoresis (7.5% SDS-PAGE), followed by staining with PAS (sensitive to carbohydrate) and CBB (sensitive to protein) for assay with a chromatoscanner. Urine samples were additionally assayed for albumin, sialic acid and acid-soluble protein. As for advanced diabetic nephropathy, many glycoproteins appeared in the urine at rest. The molecular weights (MW) of the major glycoproteins detected in the urine at rest were 53,000 and 33,000. In healthy controls, urine collected after exercise contained no glycoproteins. However, in patients with incipient diabetic nephropathy, the MW 53,000 and 33,000 glycoproteins were present. Moreover, the levels of these two glycoproteins were higher than that of the urine at rest. In addition, postexercise urine from diabetics showed significantly elevated levels of sialic acid and acid-soluble protein. These results indicate that analysis of glycoprotein patterns in the urine at rest and after exercise is useful for the diagnosis of early diabetic nephropathy.