Assessment of Intestinal Permeability in Rats by Permeation of Inulin-Fluorescein

Abstract

The measurement of intestinal permeability is widely used to assess different aspects of mucosal barrier disorders and related disease states, and has been proposed for evaluation of disease activity. To provide a simple method for assessment of intestinal permeability, we examined the permeation of inulin-fluorescein (InFl) in rat models of small intestinal injury and colitis. Small intestinal or colonic inflammation was induced by either i.p. administration of indomethacin or rectal administration of trinitrobenzene sulfonic acid (TNBS), respectively. For monitoring of intestinal permeability, InFl was administered orally or rectally to rats with small intestinal or colonic inflammation, respectively, and its level in blood was determined by the fluorescence intensity in the plasma. In small intestinal injury, InFl reached its peak in plasma 3 h after oral administration, while in colitis the InFl peak was reached 1 h after rectal administration. The highest permeability was observed at 72 h or 12 h after induction of small intestinal or colonic inflammation, respectively. In small intestinal injury the InFl permeation, as measured by its plasma level prior to sacrifice, was in agreement with intestinal damage evaluated after sacrifice. In colitis, the permeability at 12 h after induction of the disease correlated well with mortality. These findings demonstrate that InFl can be used as a novel, safe and easy-to-use probe for the evaluation of gut permeation and follow-up of gastrointestinal injury.

A review of radiation countermeasures focusing on injury-specific medicinals and regulatory approval status: part I. Radiation sub-syndromes, animal models and FDA-approved countermeasures

“…The conventional histological endpoint in mice is the regenerating crypt numbers counted in the cross section of jejunum (3.5 d for mouse jejunum); jejunal crypt cell survival may not always correlate with animal survival due to the impact of probable simultaneous damage to the immunohematopoietic system (Mason et al 1989). Functional analysis of GI damage includes the bacterial translocation into the peripheral blood stream, GI motility and permeability, and citrulline levels in blood plasma (Kobayashi et al 1991;Krimsky et al 2000;Lutgens et al 2005). Radiation-stimulated vomiting as an endpoint has been extensively studied in canines; however, the mechanisms underlying this symptom are not entirely clear, as induced responses do not precisely correlate between humans, NHP, or canines (Dubois et al 1984;Lang et al 1986;Danquechin Dorval et al 1985;Makrauer et al 1999).…”

Models for the Development of Radiation Countermeasures

“…Death due to damage to gastrointestinal (GI) tract and resultant systemic failure and histopathological evaluation of the number of regenerating crypt in murine model are some of the reliable endpoints for evaluating protective and mitigating agents. GI tract motility and permeability, bacterial translocation into the blood stream, and citrulline levels in plasma, and retrograde giant contraction which precedes vomiting and occurs on exposure to low doses are also sensitive end points 43,44 . Both canine and non-human primates are sensitive models for evaluating drugs to radiation-induced GI tract damage as they respond excellently to radiation-induced vomiting and diarrhea.…”

Nutraceutical Properties of Milk Fat Globular Membrane

“…has previously been shown to induce monocyte adhesion and infiltration into intestinal tissues of mice and induce intestinal distress (Peterson et al 2008). To assess intestinal permeability, mice were gavaged with 4000 Da Dextran-FITC (Sigma) suspended in PBS immediately after vehicle control or LPS injection (Krimsky et al 2000). After injection and gavage, animals were serially harvested at 24 h and 48 h by CO 2 asphyxiation.…”

“…In a preliminary study we saw no changes in the appearance of plasma fluorescence after LPS injection at 0 and 12 h with peak fluorescence occurring at 24 h (data not shown). These time points and animal numbers have been used successfully to determine statistical differences in membrane integrity (Krimsky et al 2000). Serum, liver, femur, and muscle samples were taken and stored for future analysis.…”

“…Dextran-FITC permeation of the gut has shown to be a sensitive indicator of gut barrier integrity in vivo and serum dextran-FITC levels are positively correlated with intestinal insult (Krimsky et al 2000). Serum cytokine analysis was performed on samples from all time points using the Q-Plex™ Mouse Cytokine -Screen (16-plex) array (Quansys Biosciences, Logan, UT, USA).…”