Figure 2.

TRPV1 on human submucosal neurons of PI-IBS patients is more sensitive compared to healthy volunteers and post-infectious healthy volunteers. (A) Representative traces of the intracellular Ca²⁺ response of human submucosal neurons in biopsies of healthy volunteers (HV, blue) (n = 7), IBS patients (red) (n = 6) and PI-HV (green) (n = 3) to acute application of capsaicin (1 nM). (B) Data showing the amplitude of the Ca²⁺ flux (%) and the number of responding neurons to capsaicin (%) in PI-IBS patients (red, n = 6), HV (blue, n = 7) and PI-HV (green, n = 3). Data are presented as median + interquartile range (left) and mean + SD (right). *p < 0.05, **p < 0.01, ***p < 0.001 (PI-IBS vs. HV); ^$p < 0.05, ^$$$p < 0.001 (PI-IBS vs PI-HV), Two-way ANOVA (left) and Fisher’s exact test (right). (C) Relative mRNA expression for TRPV1 normalized to β-actin in rectal biopsies of HV (n = 9) and PI-IBS (n = 8) patients. Statistical analysis by Mann-Whitney U test. HV = healthy volunteer, PI-IBS = post-infectious irritable bowel syndrome, PI-HV = post-infectious healthy volunteer, TRP = transient receptor potential.