Differential effects of anti-inflammatory drugs on fluid accumulation and cellular infiltration in reverse passive arthus pleurisy and carrageenan pleurisy in rats.

At 4 h following induction of pleural inflammation in rats using either an immune stimulus (reverse passive Arthus reaction, RPAR) or a chemical stimulus (carrageenan), the cellular infiltration and fluid accumulation responses were quantitated. The bell-shaped antigen (BSA) dose-response curve describing the fluid response was increased upward as the anti-BSA dose was increased from 0.25 to 1 mg, whereas the dose-response curve for cellular infiltration was both shifted upward and to the right. Both nonsteroidal anti-inflammatory drugs and a mixed lipoxygenase-cyclooxygenase inhibitor (BW 755C) preferentially inhibited fluid accumulation in RPAR pleurisy elicited with 5 mg BSA and 1 mg anti-BSA and in carrageenan pleurisy. In contrast, these drugs inhibited cellular infiltration preferentially in RPAR pleurisy elicited with 1 mg BSA and 1 mg anti-BSA. These results demonstrate that the fluid and cellular responses in rat pleural inflammation can be differentially regulated by anti-inflammatory drugs depending upon the doses of antigen and antibody employed in RPAR pleurisy and the identity of the inflammatory stimulus.