Fig. 3. NSP4 deletion decreases histamine and serotonin but does not impact mast cell numbers in the peritoneum in vivo.

a Experimental setup for ovalbumin (OVA)-induced allergic peritonitis mouse model. b Histamine and serotonin levels in the peritoneal cavity of wild-type and Prss57−/− littermates before and after OVA-induced allergic peritonitis. Bars represent mean; n = 8 biological replicates per genotype; **P < 0.01 and ***P < 0.001; two-way ANOVA and Bonferroni post hoc test. c Flow cytometry-based quantification of adult mast cells and mast cell progenitors isolated from the peritoneal cavity of Prss57+/+ and Prss57−/− littermates. Bars represent mean; n = 6 biological replicates per genotype; Student’s t test. d Toluidine blue-stained flat mounts of the mesenteric window from Prss57+/+ and Prss57−/− littermates. Scale bar, 0.5 mm; inset scale bar, 0.25 mm. e Mast cells were quantified in 10 mm² regions of interest (ROIs) in Toluidine blue-stained mesenteric window preparations. Fifteen randomly selected ROIs from three Prss57+/+ mice, and eight randomly selected ROIs from three Prss57−/− littermates were quantified, ns (not significant), P > 0.05, Student’s t test. Data shown are representative of at least two independent experimental repeats.