Intracellular cAMP levels in WT and A2BKO BMMCs. A, Cyclic AMP accumulation in WT and A2BKO mast cells incubated in the presence of 1 μM forskolin, 10 μM NECA, 1 μM CGS21680 or their vehicle (Basal). Values are expressed as mean ± SEM of five separate cell preparations. *, p < 0.05, significant difference between corresponding WT and A2BKO values determined using unpaired two-tail t test. B, Effects of 100 nM MRS1706, 1 μM DPCPX, or their vehicle on cAMP accumulation in the absence (MRS1706, DPCPX, or Basal, respectively) or presence (NECA+MRS1706, NECA+DPCPX, or NECA, respectively) of 10 μM NECA. Values are expressed as mean ± SEM of five separate cell preparations. *, p < 0.05, significant difference from vehicle in NECA-stimulated WT BMMCs determined using one-way ANOVA with Dunnett’s posttest.