Objective: To investigate the effects of mucopolysaccharide induction after treatment by low power laser for experimental osteoarthritis (OA).Methods: Seventy-two rats with three different degrees of papain induced OA over right knee joints were collected for heliumeneon (HeeNe)laser treatment. The severity of induced arthritis was measured by 99mTc bone scan and classified into three groups (IeIII) by their radioactivityratios (right to left knee joints). The rats in each group were further divided into study subgroups (Is, IIs, and IIIs) and control subgroups(Ic, IIc, and IIIc) randomly. The arthritic knees in study subgroups received HeeNe laser treatment, and those in controls received sham lasertreatment. The changes of arthritic severity after treatment and follow-up 2 months later were measured. The histopathological changes wereevaluated through light microscope after disarticulation of sections (H.E. stain), and the changes of mucopolysaccharide density in cartilagematrix were measured by Optimas scanner analyzer after Alcian blue (AB) stain. The densities of mucopolysaccharide induced after treatmentin arthritic cartilage were compared and correlated with their histopathological changes.Results: The density of mucopolysaccharide rose at the initial stage of induced arthritis, and decreased progressively in later stages. The densitiesof mucopolysaccharide in treated rats increased upon complete laser treatment more than those of the controls, which is closely relatedwith the improvement in histopathological findings, but conversely with the changes in arthritic severity.Conclusion: HeeNe laser treatment will enhance the biosynthesis of arthritic cartilage, and results in the improvement of arthritic histopathologicalchanges.
OsteoArthritis and Cartilage, v. 14, 2006, p. 377-383