Differences in the concentration of various synovial fluid constituents between the distal interphalangeal joint, the metacarpophalangeal joint and the navicular bursa in normal horses

As a prerequisite for the identification of navicular disease markers, the concentrations of cartilage oligomeric matrix protein (COMP). total glycosa minoglycans (GAG), hyaluronan, metalloproteinases (MMP) 2 and 9 and total p rotein were measured in synovial fluid samples obtained from the distal int erphalangeal joint (DIP!, the metacarpophalangeal joint (MCP) and the navic ular bursa of 24 horses, Mean GAG, COMP and total protein levels were signi ficantly higher in the DIP joint and in the navicular bursa compared to the MCP joint. Hyaluronan content was lower. MMP-2 activity was present in all fluids measured and had similar levels in different joints. MMP-9 was pres ent in 42 per cent of MCF joint samples and 58 per cent of DIP joint sample s and of navicular bursal samples. In relation to the constituents measured , the composition of navicular bursal fluid was similar to the articular sy novial fluids, in particular that obtained from the Dir joint. Correlation between the constituents of DIP joint fluid and navicular bursal fluid obta ined from the same legs was statistically significant for all the parameter s measured. (C) 2000 Harcourt Publishers Ltd.