The effect of antiinflammatory drugs on plasma fibronectin.

When rats were injected with Freund's adjuvant to induce arthritis, systemic disease as measured by swelling of the noninjected paw, was paralleled by a 100% rise in plasma fibronectin as measured by electroimmunoassay. When arthritic rats were given daily oral doses of nonsteroidal antiinflammatory drugs (NSAID), swelling of the noninjected rear paw was significantly less than that of the untreated arthritic controls. However, in all cases, plasma fibronectin (Fn) levels remained high in drug treated arthritic rats. Whether the NSAID was aspirin (100 mg/kg), phenylbutazone (10, 30, or 100 mg/kg) or indomethacin (0.3, 1 or 3 mg/kg) the pattern remained the same--reduced paw volume and unchanged high plasma Fn levels. Fn levels also remained unaltered in normal animals treated with drugs alone. Though NSAID diminish inflammation, clinical studies have shown that they do not halt disease progression. Our report shows that NSAID also fail to alter production of high levels of plasma Fn.