Abstract
Aim: It is well known that enteric nervous system (ENS) is essential for peristaltic movements and interstitial cells of Cajal (ICC) are essential for spontaneous motility such as pendular or segmenting movements. However, it is still controversial that ICC are essential for generating peristaltic movements. The aim of the present study was to clarify the roles of ENS and ICC on peristaltic movements. Method: Intestinal segments were excised from male mice (WBB6F1- W/Wv and +/+). Segments of the terminal ileum, 4.0 cm in length were placed in a 50 ml bath containing Tyrode solution (37°C) and oxygen bubbled in the bath. The contractions in the direction of the longitudinal muscle were recorded with an isometric force transducer and the contractions in the direction of the circular muscle were recorded with a pressure transducer. Mechanical activity was sometimes recorded by a digital video camera and video recordings were subsequently analyzed. Results: We compared the spontaneous motility under the hydrostatic pressure of 0∼0.5 cmH2O. In +/+ mice, marked peristalses were evoked, although they were not completely conductible from oral to anal end of the segment. L-NAME enhanced the frequency and conductivity of peristalses, but TTX abolished peristalses. In W/Wv mice, no peristalses were found, although irregular spontaneous movements were observed. L-NAME enhanced the frequency and amplitude of these movements. TTX sometimes attenuated but not abolished these movements. Conclusion: We concluded that both ICC and enteric nervous system are essential for generating peristalses at least in the ileum of mice [Jpn J Physiol 55 Suppl:S191 (2005)]
