alcian-blue and Diabetic-Retinopathy

In diabetic nephropathy, increased excretion of glycosaminoglycans and loss of basement membrane anionic charge had been documented to be related with diabetic microalbumuniria. There was no study that studied those two factors in clinical settings with a degree of diabetic retinopathy in type 1 diabetics.. Forty subjects (aged 27.3 +/- 6.3) with type 1 diabetes with different levels of diabetic retinopathy and 30 healthy subjects (aged 29.52 +/- 8.7) were included in the study. Subjects were first divided as patients without (R0) and with (R1) retinopathy. They then were further divided into two subgroups with the help of fundus angiography as diabetic lesions demonstrable with fluorescein angiography (R1A) and early diabetic retinopathy lesions on fundus examination (R1B). Erythrocyte anionic charge (EAC) was determined by the binding of cationic dye, alcian blue, and urinary glycosaminoglycan excretion and (UGAG) was determined spectrophotometrically.. UGAG was increased (35.74 +/- 14.01 vs 21.25 +/- 6.19 micro g/mL, 95% confidence intervals [CI], 9.01-19.96, p = 0.02) and EAC (62.14 +/- 27.17 vs. 158.53 +/- 36.98 ng alcian blue 106 per 106 RBC, 95% [CI] -111.68-81.10, p = 0.0001) was decreased significantly in diabetic patients with respect to controls. As the grade of diabetic retinopathy increased, UGAG increased and EAC decreased within subgroups of diabetic patients (p < 0.005). UGAG positively correlated (r = 0.36 and p = 0.03) and EAC negatively (r = -0.695, p = 0.0001) correlated with diabetes duration. EAC and UGAG negatively correlated (r = -0.58 and p = 0.0001) with each other in type 1 diabetics. EAC (p = 0.007) and diabetes duration (p = 0.001) were found to be the two significant factors to have diabetic retinopathy in diabetics with logistic regression analysis.. Although we need more prospective and larger studies to get a direct conclusion, we found that type 1 diabetic patients with less EAC and more UGAG are more likely to have diabetic retinopathy.

Topics: Adult; Alcian Blue; Anions; Blood Glucose; Diabetes Mellitus, Type 1; Diabetic Retinopathy; Erythrocyte Membrane; Female; Glycosaminoglycans; Humans; Male

The Steno hypothesis states that changes in basement membrane anionic charge leads to diabetic microvascular complications. In diabetic nephropathy, loss of basement membrane glycosaminoglycans and the association between glomerular basement membrane heparan sulphate and proteinuria has been documented. A correlation between erythrocyte surface and the glomerular capillary wall charges has also been observed. The aim of this study is to evaluate the relationship between retinopathy and erythrocyte anionic charge and urinary glycosaminoglycan excretion in type 2 diabetic patients.. 49 subjects (58 +/- 7 yrs, M/F 27/22) with type 2 diabetes with proliferative retinopathy (n = 13), nonproliferative retinopathy (n = 13) and without retinopathy (n = 23) were included in the study. 38 healthy subjects were selected as control group (57 +/- 5 yrs, M/F 19/19). Erythrocyte anionic charge (EAC) was determined by the binding of the cationic dye, alcian blue. Urinary glycosaminoglycan and microalbumin excretion were measured.. EAC was significantly decreased in diabetic patients with retinopathy (255 +/- 30 ng alcian blue/10(6) RBC, 312 +/- 30 ng alcian blue/10(6) RBC for diabetic and control groups respectively, p < 0.001). We did not observe an association between urinary GAG and microalbumin excretion and diabetic retinopathy. EAC is found to be negatively correlated with microalbuminuria in all groups.. We conclude that type 2 diabetic patients with low erythrocyte anionic charge are associated with diabetic retinopathy. Reduction of negative charge of basement membranes may indicate general changes in microvasculature rather than retinopathy. More prospective and large studies needs to clarify the role of glycosaminoglycans on progression of retinopathy in type 2 diabetic patients.

Topics: Albuminuria; Alcian Blue; Anions; Blood Glucose; Coloring Agents; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Erythrocyte Membrane; Female; Glycosaminoglycans; Humans; Male; Middle Aged; N-Acetylneuraminic Acid

The retinal vessels from seven diabetic patients and from six age-matched normal controls were studied qualitatively and quantitatively using various histological staining techniques. In diabetic patients the walls of retinal arterioles and capillaries showed significantly more staining than normals for periodic acid Schiff (neutral glycoproteins), Sirius red (connective tissue), and for Alcian blue at pH 2.6, pH 5.8 and at pH 5.8 combined with MgCl22 in concentrations less than 0.9 M (acid mucopolysaccharides). In the retina from diabetic patients there was no difference between the number of capillaries staining with these dyes in areas of vascular occlusion, and in adjacent control areas. Furthermore, in areas of vascular occlusion, the material accumulated centrally to occlude the lumen of ghost vessels did not stain with any of the dyes used. A homogenous material, accumulated in the outer retina in areas of vascular occlusion in the retina from diabetic patients, only stained with Alcian blue at pH 5.8 combined with MgCl2 in concentrations less than 0.4 M, suggesting a different molecular composition from the Alcian blue material accumulated in the retinal vascular walls. The findings are in accordance with the knowledge that basement membranes of retinal vessels are thickened in diabetes mellitus. However, the findings also indicate that basement membrane thickening cannot fully account for vascular occlusion in diabetic retinopathy.

Topics: Aged; Aged, 80 and over; Alcian Blue; Arterioles; Azo Compounds; Basement Membrane; Capillaries; Coloring Agents; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Humans; Male; Middle Aged; Periodic Acid-Schiff Reaction; Retinal Artery Occlusion