The effects of some anti-arthritic drugs and cytokines on the shape and function of rodent macrophages.

Non-steroidal antiinflammatory drugs (NSAID) enhanced the spreading of mouse and rat peritoneal macrophages attached to either plastic or glass. This was probably due to drug inhibition of prostaglandin E2 (PGE2) production since spreading was also inhibited by adding exogenous PGE2. Corticosteroids (dexamethasone, cortisol and prednisolone) and some immunosuppressants (6-mercaptopurine, methotrexate, but not cyclosporin-A) also enhanced in-vitro spreading of murine peritoneal macrophages. Some recombinant cytokines (human tumour necrosis factor alpha and beta, murine tumour necrosis factor alpha, and murine interferon gamma, but not human interferon gamma) also enhanced the spreading of mouse peritoneal macrophages in vitro. Scanning electron microscopy revealed significant differences in morphology of cells induced to spread by these drugs and cytokines. NSAID treatment also enhanced macrophage clumping in vitro, indicating that cell spreading may play an important role in the resolution of inflammatory processes and/or the formation of multinucleated giant cells.