Glycoprotein Changes in Diabetic Kidneys

A study of glycoproteins from renal cortical tissue from seventeen individuals with diabetes mellitus and four controls was performed. The diabetic tissues were divided, based on observations of the acid mucopolysaccharide composition from an earlier study, into three groups: seven showed a milder clinical course of diabetes and minimal histologic changes; five had severe clinical diabetes and predominantly nodular Kimmelstiel-Wilson lesions; and the remaining five had moderate to severe clinical diabetes with predominantly diffuse intercapillary glomerulosclerosis. In the latter two groups, a marked increase of neutral sugars was noted, particularly suggesting an increase in galactose-containing glycoprotein. Similarly, shifts to electrophoretically faster-moving glycoproteins and more intense PAS'staining were noted in severe diabetic changes. These observations suggest that there may be significant chemical changes in the nature of glycoproteins asociated with diabetes which may reflect on an uncontrolled metabolic defect of this disease.