Arachidonate metabolites in acute and chronic allergic air pouch inflammation in rats and the anti-inflammatory effects of indomethacin and dexamethasone.

Two types of allergic air pouch inflammation, the acute and the chronic types, were induced in the dorsum of rats. 1, 8, and 24 h after the immunologic challenge injection, the exudate contents of cyclooxygenase products, prostaglandin (PG)E2, 13,14-dihydro-15-keto-PGE2, PGI2 (measured as 6-keto-PGF1 alpha) and PGD2, and the lipoxygenase products, hydroxyeicosatetraenoic acids (HETEs) and 6-sulfido-peptide-containing leukotrienes (SRS) were measured by radioimmunoassay. The effects of locally injected indomethacin or dexamethasone on the exudate volumes and the number of cells in the exudates in both types of allergic inflammation and the effects of these drugs on the contents of the cyclooxygenase and lipoxygenase products in the exudates 8 h after the challenge injection were examined.