Endogenous nitric oxide production in canine osteoarthritis: Detection in urine, serum, and synovial fluid specimens.
OBJECTIVE
To measure nitric oxide (NO) concentrations in serum, urine, and synovial fluid (SF) of dogs with naturally occurring cranial cruciate ligament (CCL) rupture and normal dogs, and to compare these with clinical and histologic changes of osteoarthritis (OA).


METHODS
Prospective clinical study including 2 groups of animals selected from the hospital population.


METHODS
Forty-three dogs (CCL group) with OA secondary to CCL rupture; 30 healthy dogs (control group) without CCL rupture.


METHODS
Serum, urine, and SF were collected before and during surgery in the CCL group or immediately after euthanasia in the control group. Articular cartilage and synovial membrane tissue specimens were prepared for routine histologic examination. The stable end products of NO, total nitrite and nitrate (NOt) activity, were measured in body fluids and compared with macroscopic and histologic degrees of OA. Urinary NOt concentration was compared with urinary creatinine concentration and stated as urinary NOt:creatinine ratio (UNCR). RESULTS-SF NOt concentrations were not significantly different between the 2 groups. Serum NOt concentrations (45.6 vs 28.9 micromol/L; P =.042) and the UNCR (0.007 vs 0.004; P =.035) were significantly higher in dogs of the CCL group compared with the control population. An association between UNCR and histologic and macroscopical OA grades could be demonstrated.


CONCLUSIONS
UNCR might be a useful indicator of nitrite and nitrate production and, therefore, osteoarthritic changes in joints.


CONCLUSIONS
UNCR could be used as a tool to evaluate the NOt production by joint tissues over time and might therefore provide a method of evaluating the effects of drugs in the control of osteoarthritis.
Division of Small Animal Surgery, Faculty of Veterinary Medicine, University of Berne, Switzerland.
D
D
Spreng
N
N
Sigrist
A
A
Schweighauser
A
A
Busato
P
P
Schawalder
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000378:metabolism; D000070598:Anterior Cruciate Ligament Injuries; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000097:blood / Q000652:urine; D020370:Osteoarthritis, Knee / Q000209:etiology / Q000378:metabolism / Q000662:veterinary*; D011446:Prospective Studies; D012421:Rupture / Q000150:complications / Q000662:veterinary; D013582:Synovial Fluid / Q000378:metabolism*
D009569:Nitric Oxide