Inflammation, Impaired Motility, and Permeability in a Guinea Pig Model of Postoperative Ileus

Abstract

Background/AimsPostoperative ileus (POI) is characterized by impaired propulsive function of the gastrointestinal tract after surgery. Although inflammation is considered to be an important pathogenesis of POI, significant data are lacking. We aim to correlate the recovery time of postoperative dysmotility with that of inflammation and mucosal permeability. MethodsAn experimental POI model of guinea pig was used. Contractile activity of the circular muscle of the stomach, jejunum, ileum, and proximal colon was measured through a tissue bath study. Inflammatory cells were counted, and the expression of calprotectin and tryptase were analyzed. The expression of protease-activated receptor 2 (PAR-2), claudin-1, and claudin-2 were analyzed with immunofluorescence. ResultsThe small bowel and colon showed decreased contractile amplitude in the POI groups compared to control. In contrast to the colon, the contractile amplitude of the small bowel significantly recovered in the POI group at 6 hours after the operation compared to the control group. Inflammation was highly significant in the POI groups compared to the control and sham groups, especially in the colon. Immunofluorescence showed increased PAR-2 expression in the POI groups compared to sham. The decreased claudin-1 expression and increased claudin-2 expression may suggest increased mucosal permeability of the small bowel and colon in the POI groups. ConclusionsIncreased inflammation and mucosal permeability may play an important role in the differential recovery stages in POI. These data may provide further insights into the pathophysiology and potential new therapeutic prospects of POI. (J Neurogastroenterol Motil 2018;24:147-158)

An altered composition of fecal microbiota, organic acids, and the effect of probiotics in the guinea pig model of postoperative ileus

“…40,42,43 In line with previous studies, the present study has demonstrated that the population sizes of Bifidobacterium and Lactobacillus decrease in POI groups (Figure 3B,C). Since the inflammatory response and barrier dysfuction have been suggested as the possible main mechanism of POI, 44,45 these findings may aid understanding of the development of POI.…”

Corticotrophin‐releasing factor‐mediated effects of DA‐9701 in Postoperative Ileus Guinea Pig Model

“…The 2 cm portion of the proximal colon was removed and washed in phosphate‐buffered saline (PBS) and then immediately transfer to 4% paraformaldehyde in 0.1 M phosphate buffer (PB, pH 7.4). We selected the proximal colon with the most severe inflammation and decreased contractile activity in the POI state among the peripheral in our previous experiments . Paraffin sections (5 μm) of the whole thickness of the GI segment were processed for immunohistochemistry.…”

“…We selected the proximal colon with the most severe inflammation and decreased contractile activity in the POI state among the peripheral in our previous experiments. 20 Paraffin sections (5 μm) of the whole thickness of the GI segment were processed for immunohistochemistry. Tissue sections were deparaffinized in xylene for 60 min at 60°C and then rehydrated with 100%, 90%, and 70% alcohol successively.…”

Effects of 17beta;-Estradiol on Colonic Permeability and Inflammation in an Azoxymethane/Dextran Sulfate Sodium-Induced Colitis Mouse Model

“…That is, the expression of Zonula occludens-1 (ZO-1) and occludin (OCLN) was down-regulated in CRC, but the expressions of claudin (CLDN) 1, 2, 3, and 4 were up-regulated in CRC. 24 In addition, an over expression of protease-activated receptor 2 (PAR-2), which is a family member of G protein-coupled receptors, associated with the increased mucosal permeability in a guinea pig model of postoperative ileus 25 and reflux esophagitis in human. 26 …”