Preservation of peristaltic reflex in hypertrophied ileum of guinea pig

K. Schulze-Delrieu, B. Brown, B. Herman, C. K. Brown, D. Lawrence, S. Shirazi, Tina L Palmieri, J. Raab

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

Chronic obstruction of the guinea pig ileum leads to distension and muscular hypertrophy, but how this affects passive biomechanical and nerve- mediated contractions and clearance known as peristaltic reflex is unclear. Ileum of controls had a diameter of 3.0 ± 1.1 mm and a circular muscle thickness of 37.2 ± 11.2 μm; 4 wk after placement of a nonconstricting Gore-Tex band, the ileum was distended to 10.0 ± 0.19 mm, and its muscle had hypertrophied to 195.0 ± 61.2 μm. Hypertrophied segments exceeded controls in capacity (e.g., 5.1 ± 1.1 vs. 1.1 ± 0.2 ml at 6 cm), compliance, and hysteresis. Threshold volumes and pressures that triggered the reflex were 3.3 ± 1.3 ml and 3.1 ± 0.01 mmHg in hypertrophied vs. 0.7 ± 0.2 ml and 1.5 ± 0.2 mmHg in controls. The diameter increase that triggered the reflex was 1.4 ± 0.1 mm in hypertrophied segments and 0.6 ± 0.1 mm in controls. Hypertrophied segments generated fewer contractions of virtually double the amplitude and failed to generate a pressure differential between up- and downstream sites as controls did. Hypertrophied segments generated larger stroke volumes and cumulative clearance than controls. The ratio of antegrade to retrograde clearance was similar in hypertrophied and control segments. The length of the occluding segment in hypertrophied preparations exceeded that of controls. Control contractions indented the antimesenteric border and propagated antegrade from their site of origin; bizarre writhing movements of hypertrophied segments made their contractions difficult to monitor. Thus distension and muscular hypertrophy do not interfere with the ability of the chronically obstructed guinea pig ileum to generate a peristaltic reflex at least as readily and as powerful and as effective in clearing the lumen as controls.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume269
Issue number1 32-1
StatePublished - 1995
Externally publishedYes

Keywords

  • compliance
  • guinea pig ileum
  • hydromechanical effects of contractions
  • myenteric plexus
  • strain
  • stress
  • visceral smooth muscle hypertrophy
  • visual parameters of intestinal movements
  • wall tension

ASJC Scopus subject areas

  • Physiology
  • Gastroenterology
  • Agricultural and Biological Sciences(all)

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    Schulze-Delrieu, K., Brown, B., Herman, B., Brown, C. K., Lawrence, D., Shirazi, S., Palmieri, T. L., & Raab, J. (1995). Preservation of peristaltic reflex in hypertrophied ileum of guinea pig. American Journal of Physiology - Gastrointestinal and Liver Physiology, 269(1 32-1).