CYCLO-OXYGENASE PRODUCTS IN CARRAGEENIN-INDUCED INFLAMMATION

Prostaglandin (PG) E2, thromboxane (TX) B2 and the stable breakdown product of prostacyclin, 6-oxo-PGF1α are present in carrageenin-induced inflammatory exudates. Carrageenin-impregnated polyester sponges were implanted subcutaneously in rats and inflammatory exudates were collected 4-192 h after implantation. The concentrations of cyclo-oxygenase products in sponge fluids was measured by radioimmunoassay after extraction and purification. All three products were detectable after 4 h and reached a peak at 12-24 h. Mean TXB2 concentrations reached 74 ng/ml at 12 h but decreased to less than 10 ng/ml after 24 h. PGE2 concentrations were 65 ng/ml at 24 h, after which there was no significant increase and then dropped to about 20 ng/ml between 96 and 192 h. 6-oxo-PGF1α reached a concentration of 33 ng/ml at 24 h which did not change significantly until levels fell to less than 10 ng/ml between 96 and 192 h. The presence of PGE2, TXB2 and 6-oxo-PGF1α was confirmed by gas-liquid chromatography and mass spectrometry. Total leukocyte numbers increased steadily and were at their highest (116.0 × 106 cells/ml) at 192 h. These results suggest that thromboxanes and prostacyclin, as well as PGE2, contribute to the acute inflammatory response. © 1979.