Characterization of motor patterns in isolated human colon: are there differences in patients with slow-transit constipation?

Abstract

Spencer NJ, Kyloh M, Wattchow DA, Thomas A, Sia TC, Brookes SJ, Nicholas SJ. Characterization of motor patterns in isolated human colon: are there differences in patients with slow-transit constipation?

Colonic Migrating Motor Complexes, High Amplitude Propagating Contractions, Neural Reflexes and the Importance of Neuronal and Mucosal Serotonin

“…71,85 However, the delay between CMMCs measured at different points down the empty isolated human colon appears to be considerably shorter than those observed in vivo (Fig. 2B), 71,85 suggesting: (1) because the isolated colons were empty descending inhibition was not effectively activated by colonic content. In fact, CMMCs observed in the isolated human colon appear to propagate in both an oral or anal direction, (2) mucosal release of 5-HT could have been compromised because of hypoxic conditions within the colonic tube because the lumen does not appear to have been perfused and (3) activation of parasympathetic nerves in vivo is necessary for strong activation of IMNs, as it appears to be in the esophagus.…”

“…2C) and are similarly coordinated over long lengths of the large intestine. 71,85 Moreover, intraluminal distension initiates a premature CMMC that is also preceded by a brief relaxation phase, i.e., distension activates descending inhibitory and ascending excitatory nerve pathways. 71,85 However, the delay between CMMCs measured at different points down the empty isolated human colon appears to be considerably shorter than those observed in vivo (Fig.…”

“…71,85 Moreover, intraluminal distension initiates a premature CMMC that is also preceded by a brief relaxation phase, i.e., distension activates descending inhibitory and ascending excitatory nerve pathways. 71,85 However, the delay between CMMCs measured at different points down the empty isolated human colon appears to be considerably shorter than those observed in vivo (Fig. 2B), 71,85 suggesting: (1) because the isolated colons were empty descending inhibition was not effectively activated by colonic content.…”

“…8 In the isolated human colon from colectomy patients with STC, CMMCs (HAPCs) occurred at a similar frequency and duration as those in mice, but appeared to occur synchronously rather than propagating over long lengths of colon. 71,85 Furthermore, there were a number of spurious contractions between their CMMCs in colons from patients with STC, 71 suggesting that tonic inhibition might be compromised. Importantly intraluminal distension evoked a premature CMMC but not the preceding inhibitory response, 85 suggesting that in these colectomy patients with STC, as in the POM-STC mice, the ascending excitatory nerve pathways are intact, but the descending inhibitory nerve pathways appear to be suppressed.…”

Neurogenic and myogenic motor activity in the colon of the guinea pig, mouse, rabbit, and rat

“…Slow myogenic contractions in the human colon can be triggered prematurely by enteric neural stimulation (6). A study of larger specimens of human colon in vitro showed cyclic propagating contractions that could be recorded over large distances and that could also be phase-advanced by enteric nerve stimulation (41). These myogenic events in human colon are clearly influenced by enteric neuronal activity but are not dependent on it.…”