Biochemical differences in human glomerular basement membrane related to diabetes and age.

Preparations of glomerular basement membrane from diabetic and young and aged normal subjects have been isolated and purified and the component carbohydrates and amino acids quantitatively determined. Diabetic membrane preparations, compared with membranes from young normal subjects, show significant increases in total hexoses, mannose, and galactose and decreases in sialic acid and glucose; the component amino acids show increases in hydroxylysine, proline, and glycine and decreases in lysine, histidine, and leucine. Basement membrane preparations from aged normals show changes in component carbohydrates and amino acids similar to, but not as great as, those seen in the diabetics.