A, Percentage of mast cell degranulation (as measured by beta-hexosaminidase release) after IgE-mediated activation using either DNP-HSA or anti-IgE stimulation in mouse and human mast cells treated with increasing concentrations of acetate (left), propionate (middle) and butyrate (right). B, Percentage of degranulation after IgE- and non-IgE (C48/80 or Substance P) mediated mast cell activation in untreated or treated (5 mM butyrate, 24 h) human mast cells. C, Effects of butyrate and propionate on IL-6 cytokine production in mouse mast cells after IgE-mediated activation. Results are pooled from 3 independent experiments performed with mouse or human mast cells from 3 different donors (n=3/group). Data represent mean ± SEM, statistical significance was tested using a one-way ANOVA test: #, significantly increased compared to non-stimulated; *, Significantly decreased compared to control (P < 0.05). * P < 0.05; ** P < 0.01; ***, ### P < 0.001. NS = not significant, DNP-HSA = Dinitrophenyl - Human Serum Albumins, Sub. P. = Substance P.