heparitin-sulfate and Galactosemias

Decreased glomerular heparan sulfate synthesis could account for the increased albuminuria observed in experimental diabetes. A similar albuminuria has been observed in galactose-fed animals. To test whether heparan sulfate synthesis is also decreased in galactosemic animals we measured the heparan sulfate synthesis in isolated renal glomeruli from streptozotocin diabetic and normal rats fed regular diets or 30% galactose diets for 11-12 weeks. Albumin excretion and glomerular heparan sulfate synthesis were determined at the time of sacrifice. As predicted by this hypothesis glomerular heparan sulfate synthesis was significantly lower in the diabetic group than in normals given regular diets (309 +/- 23 vs 487 +/- 56 dpm/mg glomerular wt.; P < 0.01), and albumin excretion greater in these diabetics than in the normals (20 +/- 4.3 vs 2.0 +/- 0.7 mg/24 hr; P < 0.002). Albumin excretion and glomerular heparan sulfate synthesis were also consistent with the hypothesis, but unpredictably reversed, in the galactose-fed diabetic group. Glomerular heparan sulfate synthesis was significantly increased in this group (713 +/- 67 dpm/mg glomerular wt.) and albumin excretion decreased (10.7 +/- 3.6 mg/24 hr) compared to the diabetic on regular diet. Some possible explanations are discussed, but the galactose effect described here remains phenomenological.

Topics: Albuminuria; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diet; Galactose; Galactosemias; Heparitin Sulfate; Kidney Glomerulus; Male; Rats; Rats, Sprague-Dawley; Streptozocin