Objectives: (1) To investigate the effects of exercise and osteochondral (OC) injury on synovial fluid (SF) chondroitin sulfate (CS) and hyaluronan (HA) concentration and chain length, (2) to compare SF and cartilage CS data from joints with OC fragmentation, and (3) to compare SF CS and HA profiles with those seen in serum from the same horses. Methods: Serum and SF were obtained from (1) normal horses after 8 weeks rest, (2) the same horses after 9 months treadmill training, and (3) horses with OC injury from racing. Articular cartilage was also collected from group 3 horses. Concentrations and chain lengths of CS and HA were determined by gel chromatography and fluorophore-assisted carbohydrate electrophoresis. Results: SF CS peak chain length in the OC injury group increased significantly (18.7 kDa) when compared to rested horses (11.6 kDa), with exercise producing an intermediate chain length (15.6 kDa). Cartilage and serum from the OC injury group had the abnormally long CS chains seen in SF from these horses. Total SF HA was significantly lower in the OC injury group compared to the rested group. Both the OC injury group and the exercised group had significant decreases in SF HA chain length compared to the rested group. Conclusions: Chain length of SF CS was increased by exercise and OC injury. Exercise resulted in a modest increase, whereas OC injury caused a marked increase. In contrast to CS, SF HA chain length was decreased by OC injury, and to a lesser extent by exercise. Chain length analysis of SF CS and HA may provide a useful tool for evaluation of joint health.
Bibliographical noteFunding Information:
This research was supported in part by USA Equestrian, Inc. Grant CG03-0545 and Pari-mutuel Wagering Trust Fund Grant 280438512. The authors thank Brett Rice for technical assistance. Published as journal series No. 651 of the University of Florida College of Veterinary Medicine.
Copyright 2008 Elsevier B.V., All rights reserved.
- Chondroitin sulfate
- Osteochondral injury
- Synovial fluid