In vivo biosynthesis and turnover of 35S-labeled glomerular basement membrane.
Renal glomerular basement membrane was labeled in vivo by the injection of tracer amounts of radioactive sulfate into normal adult rats. The biosynthesis and turnover of [35S]glycosaminoglycans in purified basement membrane was determined from the specific activity of 35S in pronase digests of basement membranes isolated 1-7 days after injection. Peak radioactive labeling occurred 24 h after injection following which the specific activity of basement membrane sulfate, expressed as cpm/microgram uronic acid, progressively declined over the ensuing period of study. The biologic half-life of radioactive sulfate in basement membrane was estimated at about 7 days, which is within the range previously reported for [35S]glycosaminoglycans in whole renal cortex. The findings indicate that 35S-labeled components of glomerular basement membrane have a relatively rapid turnover.
D000818:Animals; D001485:Basement Membrane / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000096:biosynthesis / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D011402:Pronase; D051381:Rats; D013462:Sulfur Radioisotopes
D006025:Glycosaminoglycans; D013462:Sulfur Radioisotopes; D011402:Pronase