Figure 8.

Effects of IL-17 family members on TTX-resistant and TTX-sensitive Na⁺ currents in isolated and cultured DRG neurones and CGRP release in vitro from DRG neurones from naïve WT mice. (a–d) Changes of I_max (peak current densities) in DRG neurones after bath application of IL-17B (n = 5) (a), IL-17C (n = 5) (b), IL-17D (n = 7) (c), and IL-17F (n = 7) (d). Only the neurones were included which showed increases of TTX-R currents, as indicated in (e). (e) I_max of TTX-R currents of all neurones tested with IL-17 family members. No compound was applied to control neurones. (f) Changes of TTX-S Na⁺ currents (I_max) in DRG neurones after bath application of IL-17 family members. No compound was applied to control neurones. (g) Release of CGRP from DRG neurones in vitro after cell culture for 48 h and depolarization with KCl and stimulation with IL-17A for 20 min (n = 5 per group). Illustrated CGRP concentrations show the evoked release minus the basal production in the same time in relation to total protein concentration of the DRG cell cultures. Although no significant differences in the release of CGRP between WT and IL-17KO were detectable, IL-17A (10 ng/ml) signalling increases CGRP release in WT DRG neurones (p = 0.045). *p < 0.05 CGRP calcitonin gene-related peptide.