Effects of Electroacupuncture with Different Frequencies on the Glycoconjugate Alterations in Articular Cartilage in the Ankle Joints of Complete Freund's Adjuvant-injected Rats

The aim of this study was to investigate the effects of electroacupuncture (EA) on the glycoconjugate (GC) changes in articular cartilage in the ankle of an arthritic model. Arthritis was induced by an intraplantar injection of complete Freund's adjuvant (CFA) into the hindpaw of male Sprague-Dawley rats. Bilateral EA stimulation at 2 Hz, 15 Hz and 120 Hz was applied at those acupoints corresponding to Zusanli and Sanyinjiao in man, using needles for 3-day intervals for 30 days. To determine the presence of arthritis, paw edema was measured by a water displacement plethysmometer. Edema of the hindpaw induced by CFA-injection was strongly inhibited by EA stimulation throughout the experimental period. At 30 days after CFA-injection, GC changes of articular cartilage of the ankle joint were observed using conventional and lectin histochemistry. The CFA-injected rat revealed general reduction of staining abilities and lectin affinities for GC in comparison with normal rats. Significant reductions of neutral and acidic GC were observed in interterritorial matrix and chondrocyte capsules, respectively. All lectin affinities examined except DBA were also decreased in CFA-injected rats compared to normal ones. However, EA-treated rats, showed similar staining patterns and lectin affinities for GC as to normal ones, especially neutral GC in interterritorial matrix and sWGA and RCA-1 affinities in chondrocytes. It is concluded that EA in all frequencies examined, especially 2 Hz, can attenuate inflammatory edema in CFA-injected rats through alleviation of alterations of GC components in articular cartilage.