HYALURONATE IN NORMAL HUMAN SYNOVIAL FLUID1

Abstract

Methods have been described to measure hyaluronate in very small quantities of human synovial fluid. Hyaluronate was precipitated in mucin clots formed by adding acid or a polyvalent cationic salt (hexaethylenediamine-hexoltetracobalt (III) nitrate) to weighed aliquots of synovial fluid, and was measured indirectly by determining hexosamine in these clots. These clots contained all the hyaluronate hexosamine of synovial fluid and all the hexosamine in these clots was digested and rendered dialyzable by streptococcal hyaluronidase. Non-hyaluronate hexosamine remained in the supernatant and was not digested by hyaluronidase. Hyaluronate in whole synovial fluid was also determined by measuring the fall in hexosamine after hyaluronidase digestion and dialysis of synovial fluid. These figures for hyaluronate agreed with those obtained by the mucin clot technique. The average hyaluronate concentration of normal human synovial fluid was 3.6mg/g. Hyaluronate hexosamine constituted 85% or more of the total hexosamine of synovial fluid.