Expression of Bradykinin Receptors and Effects of Bradykinin in the Interstitial Cells of Cajal from Mouse Small Intestine / 체질인류학회지

ABSTRACT

Interstitial Cells of Cajal (ICC) are pacemaker cells that generates slow waves and drive spontaneous mechanical contractions of gastrointestinal smooth muscle. Slow waves are generated the periodic activation of spontaneous inward currents (pacemaker currents). We studied the modulation of pacemaker activities by bradykinin (10-8 M) in cultured ICC with the whole cell patch-clamp technique, and the localization of bradykinin-2 receptor-immunoreactivity using double labelling immunohistochemistry in the murine small intestine. Externally applied bradykinin produced membrane depolarization in current-clamping mode. At a -70 mV of holding potential bradykinin increased tonic inward pacemaker currents. Double labelling with bradykinin-2 receptor and and c-kit was shown that ICC expressed the bradykinin-2 receptor-immunoreactivity. These results suggest that bradykinin modulates electrical activities of ICC via bradykinin-2 receptor, which may regulate gastrointestinal motility.