Effects of the DP receptor antagonist BWA868C on PGD₂-induced CD11b expression and cAMP formation in eosinophils.

(A) Leukocytes were incubated for 15 minutes with PGD₂following preincubation for 2 minutes with either BWA868C (100 nM) (○) or vehicle (●). Alternatively, cells were incubated for 15 minutes with BWA868C alone (♦). CD11b expression on eosinophils was measured as shown in Figure 2. The values are means ± SE of determinations on eosinophils from 7 individuals and are expressed as percentages of the maximal responses to PGD₂ alone, after subtraction of background values. (B) Purified eosinophils were preincubated with rolipram (15 minutes) and either BWA868C (100 nM) (○) or vehicle (●) for 2 minutes followed by incubation with PGD₂ for a further 15 minutes. Then cAMP was measured by means of a protein-binding assay. The values are means ± SE of determinations on cells from 4 individuals and are expressed as percentages of the maximal responses to PGD₂. Pvalues were determined by means of a paired t test on nonnormalized data. *, P < .05. **,P < .01. ***, P < .001.