TY - JOUR T1 - Effect of radiosynovectomy with holmium-166 ferric hydroxide macroaggregate on adult equine cartilage. JF - The Journal of Rheumatology JO - J Rheumatol SP - 321 LP - 328 VL - 31 IS - 2 AU - Olli T Mäkelä AU - Mikko J Lammi AU - Hannele Uusitalo AU - Minna Viitanen AU - Mika M Hyttinen AU - Jukka S Jurvelin AU - Eero Vuorio AU - Heikki J Helminen AU - Riitta-Mari Tulamo Y1 - 2004/02/01 UR - http://www.jrheum.org/content/31/2/321.abstract N2 - OBJECTIVE: To analyze the effect of radiosynovectomy with holmium-166 ferric hydroxide macroaggregate (166Ho-FHMA) on articular cartilage in 6 adult horses. METHODS: Arthritic changes and mechanical properties of articular cartilage were evaluated with arthroscopy and postmortem microscopic analyses. Glycosaminoglycan content was measured by safranin-O staining combined with digital densitometry, uronic acid analyses, and dimethylene blue binding assay. 35S-sulfate labeling and autoradiography were used to localize proteoglycan synthesis and to characterize proteoglycan structures using SDS-agarose gel electrophoresis. Northern hybridizations were performed to measure the mRNA levels for aggrecan and pro-a1(II) collagen in cartilage samples. RESULTS: Histological signs of degeneration were present in the articular cartilage of both control and radiosynovectomized equine joints. Radiosynovectomy did not aggravate degenerative changes or significantly alter the matrix glycosaminoglycan content. A slightly decreased size of proteoglycan monomers was observed 2 months after 166Ho-FHMA radiosynovectomy. Tissue analysis of extracted proteoglycans revealed lower 35S incorporation after radiosynovectomy, but corresponding changes could not be observed in aggrecan mRNA levels. Transient downregulation of pro-a1(II) collagen mRNA transcription was observed 5 days after 166Ho-FHMA radiosynovectomy. CONCLUSION: 166Ho-FHMA treatment did not markedly affect the composition or morphology of adult articular cartilage showing mild degeneration. However, minor degradation of proteoglycan monomers and transient downregulation of pro-a1(II) collagen mRNA were observed. ER -