Proteins of rat serum V: Adjuvant arthritis and its modulation by nonsteroidal anti-inflammatory drugs

Abstract

The effect of adjuvant arthritis (AA) on the pattern of rat serum proteins includes the upregulation of haptoglobin, orosomucoid, α₂‐macroglobulin, serine protease inhibitor‐3, thiostatin, α₁‐antitrypsin, C‐reactive protein, and the downregulation of kallikrein‐binding protein, α₁‐inhibitor III, apolipoprotein A‐I, α₂‐HS‐glycoprotein, albumin, apolipoprotein A‐IV, transthyretin and transferrin. Minor changes (± 20%) are observed for Gc‐globulin, ceruloplasmin, and α₁‐macroglobulin. AA thus grossly resembles the acute inflammatory response elicited by the injection of turpentine, although the changes in the levels of negative acute‐phase proteins (APP) are smaller in acute inflammation. Indomethacine and ibuprofen inhibit the effects of arthritis on the synthesis of rat serum proteins in different ways: The former is, on average, three times as effective as the latter. Each drug interferes differently with different proteins. In animals without AA, both nonsteroidal anti‐inflammatory drugs (NSAID) mimick the inflammatory pattern to a certain extent, with more effect on the negative than on the positive APPs. Overall, the shifts in serum protein levels parallel changes in inflammatory parameters such as joint swelling and serum interleukin‐6 (IL‐6) activity. Protein quantitation after two‐dimensional electrophoresis (2‐DE) reveals some effects of the drugs per se which escape detection by other routine tests.