Cyclic motility in canine colon: Responses to feeding and perfusion

Abstract

To further characterize colonic motility in the dog and to examine the effects of intraluminal contents, motor activity in conscious animals was recorded by perfused intraluminal catheters. Animals were studied first with the bowel intact and, later, the colon was fashioned into an isolated loop. In the fasting state, cycles of motility recurred approximately each 30 min. These consisted of sequences of phasic contractions (bursts) that migrated variable distances in either direction; stationary bursts were also recorded. The fasting patterns recorded from intact bowel and isolated loops were not different. Feeding increased colonic motility, and the mean periodicity of cyclic bursts was reduced significantly to approximately 20 min. Moreover, differences were observed between intact bowel and isolated loops in the postprandial period. Diversion of chyme from the colon significantly reduced the motor response to food, but only in the late (2-4 hr) postprandial period, when the less frequent, fasting cycle returned to the loops. Perfusion of isolated loops with chyme or saline reestablished the postprandial pattern seen in intact bowel. The results suggest that the volume, but not the composition, of luminal contents modify postprandial motility in the canine colon. Additional experiments confirmed that, in particular, volatile fatty acids were probably not important determinants of colonic motility in the dog.

Effects of extrinsic autonomic denervation and myenteric plexus transection on colonic motility in conscious dogs

“…[29][30][31][32] Construction of a diverted total colonic loop with interruption of only luminal continuity failed to change the interdigestive colonic contractile activity in dogs. 9 Shibata et al 33 isolation and extrinsic denervation did not affect regular colonic contractile activity. However, propagation patterns of the colonic contractile activity were not evaluated sufficiently in the small isolated segment.…”

“…In contrast to the upper gastrointestinal tract, the colon always displays very complicated motility patterns such as segmental constrictions, 7 contractions propagating in both orad and aborad directions, [8][9][10] and giant migrating contractions. [10][11][12] In addition, colonic motility is more difficult to study because the MMC seen in the small intestine is not present in the colon.…”

Gastrointestinal Motility After Digestive Surgery

“…[63][64][65][66][67] Sarna et al 64 reported that the basic pattern of contraction in the canine colon consists of a quiescent state and a contractile state. 64 They defi ned two patterns of contractile activity: colonic migrating motor complexes (CMMC) and colonic non-migrating motor complexes (CNMC).…”

Canine Nutritional Model: Influence of Age, Diet, and Genetics on Health and Well-Being

“…Given their similarities, the dog has been commonly used to study factors impacting motility of the stomach [59], small intestine [60], cecum [61], and colon [62][63][64] and several other gastrointestinal systems/processes, including gastric responses to biopharmaceutics [65], enteral feeding to neonates [66], intestinal cell fuel oxidative metabolism [67], and microbial fermentation [16]. For the remainder of this review, we will highlight the current evidence justifying use of the canine model for studying intestinal health and disease.…”