Functional innervation of the isolated bowel segment

The aim of this study is to investigate whether there might be an eventual change in the enteric nerve responses to electrical field stimulation (EFS) of the isolated bowel segment (IBS) created by omentoenteropexy.

In the experimental group, an IBS was created in 10 rats using the omentum as the host organ by dividing of its mesentery 4 weeks later. In the control group, a jejunal loop of identical site and length to the IBS was studied in another 10 rats as normal jejunal segment. Longitudinal muscle strips were prepared from the IBSs (n 20) and the normal jejunal segments (n = 20). The effects of atropine, tetrodotoxin, L-arginine, and L-nitroarginine methyl ester (L-NAME) on the responses to transmural EFS were examined in both the IBS and normal jejunal segment using the isometric tension recording technique.

Transmural EFS of the IBS strips produced contractile responses. Atropine and tetrodotoxin abolished the EFS-induced contractions of the IBS. Moreover, EFS-induced contractions were increased by the application of L-NAME, and were decreased by the application of L-arginine in the IBS. Mean percent change of IBS's contraction was not found statistically different from mean percent change of normal jejunal segment's contraction on the effects of L-NAME and L-arginine.

These results suggest that the IBS, created by omentoenteropexy, produced enteric nerve responses to EFS as seen as in normal jejunal segment.