In vivo changes in the intestinal reflexes and the response to CCK in the inflamed small intestine of the rat

Functional motor changes and morphological alterations have been associated with intestinal inflammation. The aim of our study was to evaluate functio nal alterations of intestinal reflexes and of the responses to CCK in the T richinella spiralis model of intestinal inflammation. Rats were prepared wi th strain gauges and electrodes in the small intestine to evaluate spontane ous motor activity, the ascending contraction of the peristaltic reflex, an d the motor responses to CCK-8 infusion. Infected animals showed increased motor activity at the duodenum and jejunum but not at the ileum. Ascending contraction was increased in both duodenum and ileum. Ascending excitation after N-omega-nitro-L-arginine was still increased as well as the residual response after atropine. Response to CCK-8 during intestinal inflammation w as changed in the jejunum, in which it turned from the inhibition shown in healthy animals to excitation. NADPH-diaphorase staining did not show any c hanges between distribution and density of positive neurons in either healt hy or infected animals. In conclusion, intestinal inflammation induces func tional changes in the motor activity that could explain the abnormal motor responses observed in inflammatory disorders.