KV7 but not dual small and intermediate KCa channel openers inhibit the activation of colonic afferents by noxious stimuli

Abstract

Despite marked coexpression of small ( Kcnn1, Kcnn2) and intermediate ( Kcnn4) conductance calcium-activated potassium channel transcripts with P2X3 ( P2rx3) or bradykinin B2 ( Bdkrb2) receptors in colonic sensory neurons, pharmacological activation of these channels had no effect on the colonic afferent response to ATP, bradykinin or luminal distension of the colon. This is in contrast to the robust inhibitory effect of the KV7 channel opener, retigabine.