The excretion of glucuronic acid and of acid mucopolysaccharides in normal human urine.

The urinary excretion of acid mucopolysaccharides has been a subject of controversy. Acid mucopolysaccharides are polymers of disaccharides composed of equimolar portions of N-acetyl or N-sulfate hexosamine and hexuronic acid, occurring either free or as esters of sulfuric acid and in loose combination with protein substances. They include such substances as chondroitin sulfate, heparin and hyaluronate. The evidence for and against the urinary excretion of chondroitin sulfate was reviewed briefly by Oliver (1) whose own experiments led him to the conclusion that an "X-body," similar in some of its characteristics to chondroitin sulfate, was one of several urine constituents which influenced the precipitation of urinary proteins. Astrup (2) was particularly interested in the excretion of heparin and devised a method for extracting from urine metachromatic substances which would inhibit clotting. His method was later used by Jacques, Napke, and Levy (3) to study in greater detail the recovery of injected heparin from the urine of humans and various animals. Metachromatic material obtained from normal urine was noted by these investigators to be so small in amount that its presence did not interfere with their study of additional metachromatic substances excreted after the injection of heparin. In studying acid mucopolysaccharides, one must to some extent be concerned with their hydrolytic products. One of the important components of most 2 acid mucopolysaccharides is hexuronic