Effect of diabetes on in vivo metabolism of [35S]-labeled glomerular basement membrane.
Glomerular basement membrane (GBM) was labeled in vivo by the injection of tracer amounts of [35S]-sulfate into normal and streptozotocin-diabetic rats. The biosynthesis and turnover of sulfated glycosaminoglycans in the GBM was determined from the specific activity of [35S] after pronase digestion of basement membranes purified from glomeruli isolated 1-7 days after injection. Peak radiolabeling of both normal and diabetic GBM occurred 24 h after injection and, when corrected for differences in serum sulfate specific activities, was less in diabetic than in normal samples. The specific activity of GBM sulfate, expressed as cpm/microgram uronic acid, progressively diminished over the ensuing period of study in both normal and diabetic samples. The rate of decrease in specific activity of [35S]-labeled GBM was not significantly different in diabetic preparations compared with that in normal controls. The findings are compatible with diminished sulfation and/or production but normal turnover of glycosaminoglycans in the renal GBM in experimental diabetes.
D000818:Animals; D001485:Basement Membrane / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000378:metabolism*; D008297:Male; D051381:Rats; D013431:Sulfates; D013462:Sulfur Radioisotopes; D014574:Uronic Acids / Q000378:metabolism
D006025:Glycosaminoglycans; D013431:Sulfates; D013462:Sulfur Radioisotopes; D014574:Uronic Acids; C013786:A73025