Characteristic motor patterns of phase II and behaviour of phase III in the fed state

Abstract

The motor pattern of the phase I1 of the migration motor complex ( M M C ) is poorly characterized and it remains t o be determined whether it differs from the fed motor-pattern. Furthermore, discrepancy exists on the disruption of ongoing M M C s b y feeding, and finally, the understanding of the behaviour of phase IIIs during enteral nutrition is incomplete. Therefore, canine intestinal motility was studied after meal and during enteral infusion o f nutrients (elemental diet, glucose, maltose, amino acids) or of hypertonic saline (300-1520 mosmol kg-I). Motility o f the proximal, mid-and distal jejunum was recorded with straingauge transducers. The motor patterns o f the interdigestive phase I I , after feeding and during enteral nutrition were ana1.vsed b y a computer. Additionally, the disruption of the M M C by food and b y enteral infusion of nutrients or hypertonic saline was investigated. The interdigestive phase I I consisted of three different contractile patterns, clustered contractions, a mixed contractile pattern and non-migrating bursts o f propagated contractions (NBPCs). NBPCs differed significantly from the phase I I I activity in several motility parameters and b y the lack o f aboral migration. Only small differences existed between the motor patterns of phase I1 and o f the fed state, whereas the motor pattern induced b y enteral infusion of an elemental diet differed significantly from that of phase I I . Ongoing M M C s o f the proximal jejunum often continued to migrate to the mid-and distal jejunum. During enteral infusion of nutrients or of hypertonic saline, phase Ills recurred. The migration o f ongoing phase Ills and the recurrence o f subsequent phase Ills decreased with increasing caloric or osmotic loads. The following conclusions were reached. (a) The phase I I of the M M C is a complex motor-pattern. N B P C s represent a n e w contractile pat-tern. (b) The M M C is a characteristic feature of the empty gut. After meal and during enteral nutrition, phase IIIs are usually suppressed but they can recur during the digestive period.

Normal equine gastroduodenal secretion and motility

“…The MMC continues in spite of ingestion of food by a horse on an ad libitum basis (i.e. grazing), which is similar to that seen in ruminants, in contrast to a post cibum switch to a 'fed pattern'essentially a prolonged Phase 11that is seen in carnivora and primates that basically meal feed (Ruckebusch and Bueno 1976;Siegle and Ehrlein 1988;Ehrlein et al 1992). It is during Phase &like activity, not during Phase 111, that most of the transit of intestinal contents occurs (Ruckebusch and Fioramonti 1975;Summers and Dusdieker 1981;Memtt and Ruckebusch 1988).…”

Patterns of Small Intestinal Motor Activity During Intraluminal Infusion of Elementary Diets in Dogs

“…Nutrients may have different effects on small intestinal motility depending on the physiologic activity at the moment the stimulus is applied: if nutrients are administered during phase I of the MMC, an expected fed pattern of irregular contractions has been observed, but if the same nutrients are instilled during late phase II, fasting activity remains unmodified [11,12].…”

The effect of osmolarity and caloric load on small bowel motility

“…Studies in dogs showed that enteral nutrient infusion of more than 0.5 kcal min −1 converts cyclical fasting activity into a so‐called postprandial pattern, until at rates of approximately 4 kcal min −1 conversion will always be triggered 3,18 . Our results demonstrate that in humans, energy loads of 1.32–3.96 kcal min −1 , lying within physiologic range of gastric emptying, always initiate such a motor response.…”