Summary
The goal of our study was to compare values of stromelysin activity in stifle joint
tissues, from dogs with osteoarthritis, secondary to naturally acquired cranial cruciate
ligament (CCL) rupture and from a control population.
Twenty four dogs (CCL group) with osteoarthritis (OA), secondary to CCL rupture, were
evaluated. The control groups consisted of 22 beagles (control #1) and 14 dogs (control
#2) without CCL rupture. Articular cartilage, synovial membrane and CCL tissue specimens
were harvested during operations in the CCL group and immediately following euthanasia
in the control groups. The specimens were submitted for routine histology and for
explant tissue cultures.
Stromelysin activity was measured in the supernatant of explanted cultures. The results
of stromelysin concentrations were reported as mean ± STD and compared to histological
cartilage degeneration, synovial membrane inflammation and ligament changes. Stromelysin
activity in cartilage explants of the CCL group (70 ± 82.5 U/g) was significantly
higher when compared to the control #1 (4.2 ± 6.3 U/g) and control #2 (15 ±10 U/g)
groups. The synovial membrane explant cultures of the CCL group produced less stromelysin
compared to the control group. Whereas ligament cultures showed a tendency toward
higher activity of stromelysin when compared to the control groups. An association
between the severity of histological OA changes in the cartilage and stromelysin activity
in cartilage explants was demonstrated. We conclude that dogs with OA, secondary to
naturally acquired CCL rupture, release higher stromelysin levels in articular cartilage
and cranial cruciate ligament explant cultures when compared to the controls. Our
results indicate that stromelysin production in articular cartilage is related to
the severity of OA.
Stromelysin, one of the major metalloproteinases degrades articular cartilage mainly
by cleavage of proteoglycans. Increased levels of stromelysin could be demonstrated
in cartilage of stifle joints from dogs with naturally acquired cranial cruciate ligament
rupture using a radioimmunoassay. There was an indication in this study that the activity
of stromelysin is associated with the severity of osteoarthritic changes.
Presented in part at the European College of Veterinary Surgeons Annual Scientific
Meeting, Pörtschach-Austria, June 1998.
Keywords
Osteoarthritis - cartilage - stromelysin - dog