Use of an isolated intestinal circuit to evaluate the effect of ischemia and reperfusion on mucosal permeability of the equine jejunum.

The research is a study examining whether an isolated perfusion circuit can effectively maintain a segment of horse intestine (jejunum) and the impact of blood supply cut-off and re-establishment (ischemia-reperfusion) on jejunum’s mucosal permeability.

Methodology

• The study was conducted in an in vitro setup using the intestines of twelve healthy adult horses.
• A control segment of the jejunum was placed in an isolated perfusion circuit for 240 minutes and the permeability of the mucosa, the innermost layer of the intestine, was measured.
• After confirming that the isolated system had no harmful effects on the control intestine, low flow ischemia (restriction of blood supply to the tissues) was induced in experimental segments for 20, 40, 60, and 90 minutes. This was followed by 60 minutes of reperfusion (restoration of blood flow) and the mucosal permeability was evaluated again.
• At the end of the experiment, histologic evaluation, an examination of the microscopic structure of tissues, was used to assess mucosal grades, surface area, and volume.

Results

• The research found that the isolated circuit managed to maintain the control tissue for a duration of 240 minutes without any effect on the mucosal grading, surface area, or volume relative to intact tissue.
• Following ischemia-reperfusion, there were observed increases in mucosal grading, and decreases in volume and surface area, which worsened with longer periods of ischemia.
• The mucosal clearance of albumin, a protein whose rate of passage through the mucosal barrier can indicate its permeability, remained constant during the 240 minutes of perfusion in control tissue but was found to be increased after ischemia-reperfusion.

Conclusion

• The research concluded that no harmful changes were observed in the jejunum when perfused with the isolated circuit.
• However, alterations in the permeability of the mucosa were observed after ischemia-reperfusion.
• The isolated perfusion circuit was successful in maintaining an isolated segment of the jejunum within physiological limits and can be used to study the effects of injury and to gauge the efficacy of drugs in mitigating these changes.