Sulfated and nonsulfated glycosaminoglycans and glycopeptides are synthesized by kidney in vivo and incorporated into glomerular basement membranes ([35S] radioactivity and 10-15% of the total 3H radioactivity incorporated into cortex, glomeruli, or GBM was found in the GAG fraction, and the remainder (--'32% of 35S radioactivity and 85-90% of the 3H radioactivity) was found in glycopeptide fractions. Treatment of GAG fractions isolated from the three sources (cortex, glomeruli, and GBM) with nitrous acid (which degrades heparan sulfates) indicated that the majority (85%, 65%, and 87%) of the 3S radioactivity as well as the majority (60%, 50%, and 91%) of the 3H radioactivity from all three sources was degraded by this treatment. When nitrous acid-resistant GAG from GBM were subjected to digestion with Streptom ces hyaluronidase (which degrades hyaluronic acid), --6% of the H-labeled material was sensitive to this treatment. The remaining 35S-and 3H-labeled GAG isolated from GBM were digested with chondro-

No abstract