Colonic and jejunal motor disturbances after colonic antigen challenge of sensitized rat.
OBJECTIVE
Inflammation in the colon may alter motility in the proximal gut and potentiate clinical symptoms. The aim of this study was to characterize the effect of colonic anaphylaxis on local (colonic) and remote (small intestinal) motility and identify the mechanism and mediators involved.


METHODS
Rats were sensitized by intraperitoneal injection of 10 microg egg albumin and surgically prepared with electrodes in jejunum and colon and a colostomy tube. Colonic and jejunal myoelectric activity were recorded in fasted animals before and after colonic antigen challenge without and then after pretreatment with specific antagonists.


RESULTS
Colonic antigen challenge of sensitized rats was associated with significant (1) increase in colonic myoelectric spike activity, (2) disruption of fasting jejunal motility and initiation of aborally propagating spike complexes, and (3) increase in plasma rat mast cell protease II levels with a decrease in granulated mast cells in colon but not jejunum. The myoelectric disturbance in both colon and jejunum was inhibited significantly by pretreatment with atropine and hexamethonium, doxantrazole, cyclooxygenase, and lipoxygenase inhibitors. Methysergide inhibited only the jejunal disturbance.


CONCLUSIONS
Colonic antigen challenge of sensitized animals results in local mast cell activation and the release of mediators that modulate neural pathways to initiate both a local colonic and a remote jejunal myoelectric disturbance.
Oliver
M R
MR
Department of Pediatrics, University of Calgary, Alberta, Canada.
Tan
D T
DT
Kirk
D R
DR
Rioux
K P
KP
Scott
R B
RB
D000418:Albumins / Q000276:immunology; D000818:Animals; D000941:Antigens / Q000276:immunology*; D003106:Colon / Q000276:immunology* / Q000502:physiology; D005769:Gastrointestinal Motility / Q000276:immunology*; D007114:Immunization; D007583:Jejunum / Q000276:immunology* / Q000502:physiology; D051381:Rats
D000418:Albumins; D000941:Antigens