Intestinal motility in an in vivo rat model of intestinal ischemia-reperfusion with special reference to the effects of nitric oxide on the motility changes

Background: To clarify the relation between intestinal ischemia-reperfusion (IR) and dysmotility, the authors investigated changes in the motility pattern in the duodenum and jejunum in an in vivo rat model of IR when artery- (and vein-) fed jejunum was clamped transiently. The authors also studied the effect of nitric oxide on the motility changes in this model by means of the administration Of L-NAME (N-G-nitro-L-arginine methyl ester) or S-methylisothiourea sulfate (SMT). Materials and Methods: A force transducer was sutured onto the serosal side of the duodenum or jejunum. After a 3- to 4-day recovery period, contractions were recorded during periods of preischemia, ischemia (60 minutes), and reperfusion (90 minutes). An intestinal IR was produced by clamping and releasing the mesenteric artery and vein with artery forceps. Results: In the jejunum, there was a prolongation in the duration of contraction and there were decreases in the number of contractions (Nc) during the IR. When treated with L-NAME, no decrease in the NC was observed during the 45 to 90 minutes after reperfusion, S-methylisothiourea sulfate did not affect the IR-induced motility changes significantly. In the, duodenum, there was a prolongation in the duration of contraction and a decrease in the NC and AC only during the reperfusion. L-NAME or S-methylisothiourea sulfate inhibited the decreases in the NC during the reperfusion. Conclusions: Intestinal IR causes motility changes in the ischemic site during the IR and in the nonischemic site during the reperfusion. The IR-induced motility changes partly depend on nitric oxide production.