Immune complexes and inflammation. A study of the activity of anti-inflammatory drugs in the reverse passive arthus reaction in the rat.

The reverse passive Arthus reaction in rat skin was quantitated by using increase in wet weight as a measure of edema and extractable myeloperoxidase as a measure of the intensity of polymorphonuclear leukocyte (PMN) infiltration. Treatment of the animal with dexamethasone prior to challenge with antigen/antibody resulted in an inhibition of both edema and the infiltration of inflammatory cells. In contrast, the non-steroidal anti-inflammatory drugs inhibited the intensity of cell infiltration (PMNs but not mononuclear cells) without affecting edema. The results are discussed in the light of the effects of these drugs on arachidonic acid oxidation.