The acute alterations in biochemistry, morphology, and contractility of rat-isolated terminal ileum via increased intra-abdominal pressure.

AIM AND SCOPE

To determine the acute effects of increased intra-abdominal pressure (IAP) on the biochemistry, morphology, and contractility of the isolated terminal ileum of rats.

BACKGROUND

Laparoscopic procedures are used clinically in diagnostic and treatment modalities and experimentally as a model of ischemia-reperfusion injury induced by the elevation of IAP. Although some clinical and in vivo experimental studies investigate the results of ischemia-reperfusion injury whether induced by elevated IAP or clamping, there is no in vitro study that has investigated the acute effects of high IAP mimicked by a laparoscopic intervention in any of the intra-abdominal organs (like terminal ileum) on the basis of contractility which represents the motility.

METHODS

Twenty-four adult with either sex Sprague-Dawley rats were divided into three groups. The control group (Group I) was not subjected to any IAP. In Groups II and III, an IAP of 10 and 20 mmHg, respectively, was established by carbon dioxide pneumoperitoneum for a period of 60 min. Thirty minutes after the desufflation, the terminal ileum was removed for in vitro pharmacological investigation, measurement of malondialdehyde (MDA) values, and histopathological examination. Statistical comparisons among groups were done using the Kruskal-Wallis variance analysis, with post hoc comparison performed with the Mann-Whitney U-test.

RESULTS

Tissue MDA value and the damage scores of mucosa and submucosa were significantly increased in both IAP groups. The smooth muscle layer was significantly damaged only in Group III. The contractions obtained by electrical field stimulation (EFS) were inhibited in both IAP groups, and the contractions to acetylcholine were inhibited in Group III when compared to the control group.

CONCLUSIONS

In conclusion, we can say that pneumoperitoneum induced IAP may inhibit contractile responses, cause structural alterations which may be related to ischemia-reperfusion injury in rat terminal ileum.