Recordings were made of spontaneous phasic contractions of longitudinal muscle of isolated proximal colon. A. Representative recordings from tgr5-wt and tgr5-ko mice. In tgr5-wt mice, UDCA (100 μΜ) had no effect, whereas DCA (100 μΜ) immediately inhibited spontaneous phasic contractions. In tgr5-ko mice, DCA was inactive. B, C. Mean results of the effects of DCA on frequency (B) and tension (C) normalized to basal values (1.0). DCA reduced the frequency and tension in tgr5-wt but not in tgr5-ko mice. * P< 0.05, *** P<0.001 to tgr5-wt.