Morphological and biochemical alterations in the jejunum following iodoacetamide-induced colitis in rats

Abstract

This study aims to describe the morphological alterations in the small and large intestines as well as the expression of some enterocyte enzymes and carriers in a rat model of iodoacetamide-induced colitis. Biopsies from the large and small intestines were taken at 1, 2, 4, 8, and 16 days postinduction and studied by light microscopy. The expressions of lactase, sucrase, aminopeptidase, and Glut-5 in the jejunum were studied by immunohistochemistry. Gene expressions of enterocyte lactase and sucrase were determined by RT-PCR using specific oligonucleotides. Microscopic examination of the large intestines revealed manifestations concordant with inflammation. Such alterations peaked at 2 days, were maintained to a lesser extent for 4 days, regressed by 8 days, and healed by 16 days. In the jejunum, the expression of lactase, sucrase, and aminopeptidase decreased 2 days after colitis induction, and recovered 2 days later. Similarly, Glut-5 expression decreased transiently with partial recovery by day 8. Compared with sham, gene expression of jejunal brush border enzymes sucrase and lactase showed a 4-fold increase in lactase and a 9-fold increase in sucrase after 4 days. We conclude that colitis can induce significant functional abnormalities in distant noninflamed small bowel regions.

Inflammatory bowel disease in rats: Bacterial and chemical interaction

“…Over the past three decades, several models of UC have been developed, with a variable range of clinical manifestations resembling those observed in human IBD, however, none of these closely mimic the clinical entity of human UC [10,11,16,17] . Using animal models, there is much indirect evidence to suggest an interaction between The combined treatment (IA + B) continued injection subgroup maintained a relatively higher level of the TNF-α mRNA compared to IA-treated or the B-treated and MC-treated control groups ( Figure 6B).…”

“…The evaluation of inflammation was performed according to the modified criteria for colonic changes (Table 1) [17,21] . Parameters like diarrhea, hyperemia, adhesions, ulceration and megacolon were assessed to describe the inflammatory status.…”

“…Serial 5 μm sections were cut and stained with hematoxylin and eosin (HE) and Periodic Acid Schiff (PAS) using standard methods. The microscopic alterations were assessed according to the criteria shown in Table 2 [17][18][19][20][21][22] , and a numerical score of the colonic abnormalities was obtained. The histologic grades ranged from 0 (normal) to 18 (intense inflammatory reaction).…”

“…Therefore, more studies are required to further develop this area of research. The iodoacetamide-induced acute UC model in rat developed by Satoh et al [16] has been extensively studied [17,18] . In this model, an array of morphological and functional alterations have been described, however, the model lacked features of chronicity [17][18][19][20] .…”

“…The iodoacetamide-induced acute UC model in rat developed by Satoh et al [16] has been extensively studied [17,18] . In this model, an array of morphological and functional alterations have been described, however, the model lacked features of chronicity [17][18][19][20] . The present study reports the successful development of a chronic UC model, using the combined effects of iodoacetamide, a sulfhydryl group blocker, and enteropathogenic E. coli (EPEC), a strain with adhesion properties, instilled repetitively into the descending colon of rats.…”