Biochemistry of glomerular basement membrane of the normal and diabetic human.

HGBM were isolated from kidneys of 22 diabetic patients and 32 normal control persons. All diabetic kidneys showed severe alterations of glomerulosclerosis. The amount of basement membranes isolated from diabetic kidneys was significantly higher. The HGBM preparations were individually analyzed for phosphorus, DNA, amino acids, and carbohydrates. The cystine concentration was found to be lower in the diabetic than in normal HGBM. Contrary to other reports, there was no increase in the amounts of hydroxylysine, glucose, and galactose, nor was there a decrease in the lysine content. Glucose and mannose were shown to be significantly lower in the diabetic HGBM. The mean value for sialic acid content was lower in diabetic HGBM; the value did not reach statistical significance. This study's data could not confirm the finding of a specific alteration of diabetic HGBM as proposed previously.