Acid Hydrolases in Slices of Articular Cartilage and Synovium from Normal and Abnormal Joints 1

Summary

Five acid hydrolases, i.e., glu-cosaminidase, sulfatase, phosphatase, cathepsin, and glucuronidase were identified in normal articular cartilage and synovium of rabbit knee joints by incubating tissue slices with appropriate substrates. These enzymes were also assayed in cartilage and synovium of rabbit knee joints which had been subjected to continuous compression from 1 to 21 days. Significant elevation of enzyme activity occurred in the first two enzymes in the cartilage and in the first four enzymes from the synovium of the treated joints. Studies with tissue slices preincubated with and without substrate suggest that most of the hydrolysis of substrate occurs within the tissue, rather than as a result of enzyme liberation into the incubation medium.