Long-term effects of myochrysine on the synovial membrane and aurosomes.

Mysochrysine injected into the rabbit knee joint produced regressive and destructive changes in the synovial membrane, ultimately leading to fibrosis. Aurosomes, containing characteristic electron-dense deposits indicating the presence of gold, formed in the synovial intimal cells and subsynovial macrophages. The number of aurosomes decreased with the passage of time but some were found even 2 yr after the injection of Myochrysine. Electron-probe X-ray analysis showed that the aurosomes contain gold, sulphur and phosphorus. A comparison was made between the atomic ratios of these elements in 3-day and 18-mth-old aurosomes but no significant difference was detected.