Effects of anti-inflammatory drugs on triple vaccine-induced pleurisy in rats.

Effects of various anti-inflammatory drugs on triple vaccine-induced pleurisy, a model of delayed hypersensitivity, were examined and compared with those on carrageenin-induced pleurisy in rats. Steroidal drugs depressed markedly the volume of exudate and the number of leucocytes in both types of pleurisy. Gold compounds also depressed both types of pleurisy. Non-steroidal anti-inflammatory drugs were apt to show depressive effects on carrageenin-induced pleurisy, especially on increased exudate volume. BW755C produced a depressive effect on carrageenin-induced pleurisy, but on triple vaccine-induced pleurisy, BW755C produced only a slight depressive effect. Cyproheptadine produced a slight depressive effect on carrageenin-induced pleurisy, but not on triple vaccine-induced pleurisy. Promethazine had a slight depressive effect on both types of pleurisy. D-penicillamine and levamisole did not show any depressive effects on triple vaccine-induced pleurisy. The results show that reported mediators in carrageenin-induced pleurisy (prostaglandin, serotonin, leukotriene B, etc.) are not relevant to triple vaccine-induced pleurisy. Specific lymphokines and/or degradated products of complement may participate in the latter. This triple vaccine-induced pleurisy seems to be a good model for screening non-steroidal anti-inflammatory drugs which have steroidal-like activity.