Comparative study of normal and osteoarthritic canine synovial fluid using 500 MHz ¹H magnetic resonance spectroscopy

Abstract

High resolution 1H nuclear magnetic resonance spectroscopy has been used to investigate and compare the metabolic profiles of normal and osteoarthritic synovial fluids in a canine model of osteoarthritis. The spectra of osteoarthritic synovial fluid showed (a) increased concentrations of lactate, pyruvate, lipoprotein-associated fatty acids, and glycerol as well as the ketones hydroxybutyrate and hydroxyisobutyrate, (b) reduced levels of glucose, and (c) elevated levels of N-acetylglycoproteins, acetate, and acetamide compared with healthy normal canine synovial fluid. An increase was also observed in the concentrations of the amino acids alanine and isoleucine. These results suggest that (a) the intraarticular environment in canine osteoarthritis is more hypoxic and acidotic than in a normal joint, (b) lipolysis may play an increasingly important role as a source of energy in osteoarthritis, and (c) the N-acetylglycoprotein polymer component of synovial fluid (mostly hyaluronan) seems to be increasingly fragmented and degraded into acetate by way of an acetamide intermediate with progressive osteoarthritis. The observed changes in the biochemical profile of canine osteoarthritic synovial fluid may be useful in understanding alterations in joint metabolism consequent to arthritic diseases and helpful in identifying potential markers of osteoarthritis.

Global metabolic profiling of human osteoarthritic synovium

“…Although not reaching significance, levels for additional TCA intermediates also trend in the direction of reduced oxidative energy metabolism with disease (Table 1). Altered metabolic profiles in urine and synovial fluid from OA patients have also suggested a role for altered energy metabolism in OA 11, 12 .…”

Metabonomic investigations in mice infected with Schistosoma mansoni : An approach for biomarker identification

“…Multivariate statistical analysis, including linear projection methods, principal component analysis (PCA), Bayesian probabilistic methods, and neural networks (14) can be applied to complex spectral data to aid visualization and characterization of changes relating to a biological perturbation. Metabonomics has become a well established analytical tool with successful applications in different fields, e.g., the study of disease processes and drug toxicity (15)(16)(17)(18), and detection of metabolites of inborn errors (19). Recent technological advances have enabled analysis of more subtle metabolic responses to challenges such as nutritional intervention (20), variation in hormonal cycles (21), gender differences, and diurnal variation (22).…”

Examination of the molecular nature of low-molecular-mass chromium(III) ions in isolated osteoarthritic knee-joint synovial fluid

“…The ketone bodies 3-D-hydroxybutyrate and acetone detectable serve as indicators of the utilization of lipids as a source of energy in view of a reduced local supply of glucose. Moreover, the glycerol detectable by this technique reflects triglyceride hydrolysis [28].…”

“…In view of the kinetic inertness associated with Cr(III) complexes, all titration samples were equilibrated for 72 h prior to final storage at À60°C until required for 1 H NMR analysis. For this reason, NMR spectra of the samples were routinely examined on a weekly basis in order to monitor any significant spectral modifications (other than those attributable to full or partial SF component biomolecule oxidation on prolonged equilibration [28]). However, it should be noted that despite the complete saturation of Cr(III) by all available SF complexants, the various kinetically favoured Cr(III) hydrolysis and hydrolytic polymerization processes, known to occur in biological systems [29] (leading to the formation of dimer, trimer, tetramer and higher oligomeric species of the type Cr x ðOHÞ zþ y [30]), are also possible products arising from the addition of this redox-active metal ion to the biofluid.…”