Figure 2. CRF₁ receptors expressed on MCs promote IgE-mediated MC degranulation and anaphylaxis in vivo.

MC-deficient Kit^W-sh/W-sh mice were engrafted with BMMCs derived from WT or CRF₁^−/− mice. AT 12 wk after engraftment, PSA was induced in mice as described in the Materials and Methods section. (A) Serum histamine levels in mice 120 min after PSA induction. (B) Change in body temperature after induction of PSA. (C) Average number of degranulated MCs per ×20 field in intestinal mesentery between treatment groups. (D) Normalized clinical disease. (E) Intestinal mesentery MC counts in Kit^W-sh/W-sh mice engrafted with BMMCs derived from WT or CRF₁^−/− mice. Data represent means ± se and were analyzed using a 2-way ANOVA with a post hoc Tukey’s test (A and B) or 2-tailed t test (C–E). *P < 0.05; **P < 0.01; *^#P < 0.05 vs. other treatment groups (ANOVA).