Small intestinal motility and transit by electromyography and radiology in the fasted and fed pig.

Abstract

SUMMARY1. The pattern of small intestinal digesta transit was studied in six young pigs (20-30 kg) by simultaneous electromyography and radiology. Pigs showed migrating myoelectric complexes (m.m.c.s) in the small intestine both when fasted and after feeding. The m.m.c.s were modified by feeding; quiescence was much reduced in duration and irregular spiking activity (i.s.a.) was prolonged; m.m.c.s were not disrupted and phases of regular spiking activity (r.s.a.) were still seen after feeding.2. The r.s.a. phase could be recognized on the screen and in spot films from both fasting and fed pigs as a band of intense rhythmic contractions pinching off the intestine and propelling all intestinal contents ahead of it. The r.s.a. moved caudad clearing the small intestine of digesta and leaving an empty quiescent intestine behind it. It was particularly characteristic in the fasted pig where it was usually associated with the progression of a gas bubble. 6. Two patterns of transport into the large intestine were seen. Usually digesta was transported by peristaltic rushes starting 100-200 cm from the ileo-caecal junction. The rush then continued through 1-11 turns of the spiral colon; occasionally the terminal ileum emptied by slow peristalsis. In this case there was no colonic rush and digesta went into the caecum.

The relationships between glucose absorption and insulin secretion and the migrating myoelectric complex in the pig

“…The MMC was modified but not disrupted by feeding as previously described (Rayner & Wenham, 1986). The first postprandial MMC was significantly (P < 0 05, n = 9) lengthened (861 + I ± 0 min) while MMCs 2-4 were the same duration (635 + 0-2 min Fig.…”

“…It recurs every 70-100 min at any one site in the pig and consists of phases of quiescence (slow waves only = phase I), irregular spiking (spikes on some slow waves = phase II) and regular spiking (spikes on all slow waves = phase III) (Carlson, Bedi & Code, 1972;Bueno, Fioramonti & Ruckebusch, 1975). Unlike other monogastric species, the MMC in the pig persists in modified form after feeding and plasma glucose and insulin concentrations appear to vary in relation to the MMC (Rayner, Weekes & Bruce, 1981;Fioramonti, Bueno & Ruckebusch, 1982); phase III activity seen within 2 h of feeding propels forward all intestinal contents, causing digesta to move in 'batches' rather than flowing continuously (Rayner & Wenham, 1986). In fasting animals concentrations of gastrointestinal hormones such as motilin and pancreatic polypeptide are known to vary with the phase of the MMC (Poitras, Lemoyne, Tasse & Trudel, 1985;Rayner, Christofides, Gregory, Goodall & Bloom, 1987).…”

Flow Behavior of Digesta and the Absorption of Nutrients in the Gastrointestine

“…Segmental contraction in the cecum and proximal colon is incomplete (33), leaving lumen space, whereas segmental contraction in the ileum is complete (34). An imaginary circular tube with a 25-or 15-mm radius was assumed, which represented the cecum and proximal colon or the ileum respectively (29,30).…”

Caracterização morfológica da região de transição entre o intestino delgado e o grosso no javali

“…Schäppi 11 descreveu esta conformação em 100% dos casos observados, entretanto seu trabalho inclui apenas cinco exemplares de javalis. Acreditamos que a variabilidade da disposição da papila encontrada em nossas observações deva-se a mobilidade da mesma diante a atividade intestinal, como descrito para suínos 46 e, talvez, seja esta sua disposição em repouso, justificando, assim, a menor altura do contorno caudal.…”

“…O javali, como o porco doméstico, apresenta digestão parcial no ceco e somos levados a concordar com as ponderações de Prado e Di Dio 30 , para suínos, que esta não seria prejudicada pela disposição ceco-cólica da terminação do íleo, devido a sua mobilidade 46 . 0,002167 descritos para a mesma espécie 11 e para a espécie suína 9,17 , pois as três tênias alcançavam o ápice do órgão.…”