Evidence for a steroid receptor in rheumatoid synovial tissue cells.

One mechanism by which glucocorticoids could exert their anti-inflammatory action is via rapidly saturable, stereo-specific cytoplasmic protein receptors. This report is of an investigation into such a possibility in synovial cells. Synovium, obtained from knee joints of rheumatoid patients undergoing surgery, was incubated with clostridiopeptidase A and trypsin-EDTA to obtain cell suspensions. These, together with cells obtained from synovial fluid aspirated from patients with rheumatoid arthritis, were identified by electron microscopy. Duplicate samples of these cell suspensions were incubated with increasing concentrations of H3Dexamethasone (1 x 10(-10)M-1 x 10(-9)M) for 30 minutes at 37 degrees C. Analysis of the proportion of steroid bound to whole cells showed evidence for specific, rapidly saturable, receptors in the cells obtained from synovial tissue, but this was not found in synovial fluid cells. Electron micrographs showed that cells obtained from synovial tissue consisted of synovial fibroblast - and macrophage-types, lymphocytes, monocytes and macrophages. Polymorphonuclear leucocytes appeared to be absent. However, in synovial fluid cell type polymorphonuclear leucocytes were the predominant cell type. We concluded from this, that one or more of the cell types present in synovial tissue contain a specific steroid receptor, but that this is lacking in synovial fluid polymorphonuclear leucocytes.