Cartilage and serum levels of nitric oxide in patients with hip osteoarthritis

Objective. To assess whether nitric oxide (NO) is related to cartilage dete rioration resulting from osteoarthritis, NO concentrations were analyzed in normal and deteriorated areas of cartilage obtained from femur heads of pa tients with primary hip osteoarthritis (HOA). Methods. The concentration of NO in macroscopically deteriorated and non-de teriorated cartilage of femoral heads of patients with HOA at hip replaceme nt surgery was analyzed spectrophotometrically. Serum NO levels were also d etermined in 16 ambulatory patients with hip OA and in healthy volunteers. Results. NO levels of non-deteriorated areas of femoral head cartilage were significantly lower (3.82 +/- 1.30 mu mol/l; mean +/- SD) than levels of d eteriorated cartilage areas (11.07 +/- 6.48 mu mol/l; p < 0.01). The surger y HOA group showed serum NO levels (2.64 +/- 0.32 mu mol/l; p < 0.0001 vs h ealthy group) similar to the ambulatory HOA group levels (2.56 +/- 0.56 mu mol/l; p < 0.0001 vs healthy group). Serum NO concentrations in healthy vol unteers were 1.37 +/- 0.55 mu mol/l. Conclusion. This study shows increased NO levels in joint cartilage of pati ents with hip OA. This increase was not homogeneously distributed, but the higher NO levels were found in macroscopically deteriorated areas. The data also suggest that high NO serum levels found in patients with hip OA may b e due to joint cartilage destruction.