Intraarticular glucocorticoids effects on lipoxygenase expression in rheumatoid arthritis synovium. Intraarticular glucocorticoids decrease 5-lipoxygenase (5-LO) expression in rheumatoid arthritis (RA) synovium but leave unaltered the expression of 15-LO-1 enzyme. RA synovial tissue (n = 11) showing diaminobenzidine (brown) staining for 5-LO (a) before and (b) after treatment, and for 15-LO-1 (d) before and (e) after therapy (hematoxylin counterstained). Graphs show image analysis results for (c) 5-LO and (f) 15-LO-1 expression in synovial biopsy sections taken before and after intraarticular corticosteroid injection. Results expressed as percentage of the total area of counterstained tissue. Horizontal lines, median values; whiskers, range values. **P < 0.01. Original magnification: (a, b) ×125 and (c, d) ×160.