Reduced number of anionic sites is associated with glomerular basement membrane thickening in the diabetic BB-rat

Glomerular basement membranes of diabetic and age- and sex-matched non-diabetic BB rats were studied morphometrically and ultrastructurally using a quantitative histochemical technique employing the cationic dye cuprolinic blue. Six months of diabetes resulted in a significant reduction in the density of anionic sites associated with increased thickness of the glomerular basement membrane. These findings suggest that the loss of anionic sites may be an important mechanism in the genesis of glomerular basement membrane dysfunction in diabetes.