Effects of Starvation and Bowel Resection on Paracellular Permeability in Rat Small-Bowel Mucosa in Vitro

Abstract

Background: Maintenance of intestinal integrity is essential after major abdominal surgery in malnourished subjects. The purpose of this experimental study was to investigate factors affecting small-bowel mucosa permeability in vitro in the immediate postoperative period in starved rats. Methods: Male Wistar rats were randomly placed in five groups: Controls, Anesthesia, Resection, Starvation, and Starvation + resection. Controls consisted of fed rats. Anesthesia was induced intraperitoneally with xylazine and ketamine. Resection was 5 cm of the mid-jejunum, and the starvation period was 48 h. Two hours after surgery stripped mucosal segments from the jejunum and the ileum were mounted in Ussing chambers, and the transmucosal permeation of ⁵¹Cr-labeled ethylenediaminetetraacetic acid (EDTA) and dextran (40,000 Da) was studied for 120 min while electrophysiology was monitored. Results: Starvation increased permeability to ⁵¹Cr-EDTA in both the jejunum and ileum. In the jejunum permeability was further increased by starvation + resection. Resection or anesthesia alone did not increase permeability. The villous height in the jejunum was reduced by starvation. Mucosal permeability was correlated to the change in transepithelial resistance during experiments. Conclusions: Starvation was the main cause of increased mucosal permeability in both intestinal segments of the rat, but surgical trauma had an additive effect, which was most pronounced in the jejunum.