Morphologic and ultrastructural evaluation of effect of ischemia and dimethyl sulfoxide on equine jejunum.

This research studies the morphological changes in horse’s small intestine during and after an hour of interrupted blood supply, as well as the protective role of dimethyl sulfoxide (DMSO). Using ponies as subjects, the study observed that ischemia and reperfusion caused moderate damage marked by disrupted cell connections and fluid accumulation within the tissue, while DMSO appeared to have a protective effect.

Research Methodology

• The study was conducted on 18 ponies, that were divided into four groups: a control group, DMSO group, ischemia group and ischemia with DMSO group.
• Two sections of the jejunum (part of the small intestine) were taken from each pony. The first section was collected prior to the induction of ischemia, and the next two hours later, after reperfusion.
• Morphologic changes in the jejunal segments were evaluated using light microscopy, and scanning and transmission electron microscopy.

Findings and Observations

• The combined process of ischemia and reperfusion resulted in moderate injury to the equine jejunum characterized by disruption of enterocyte (intestinal) attachment from the basement membrane and lamina propria.
• Fluid accumulation disrupted cell-to-cell cohesion at the base of the enterocyte cells, while junctional structures at the luminal surface remained unaffected.
• Damage was predominantly observed at the tip of the villus (small intestinal protrusions) and progressively worsened down the sides. Prominent changes within the cells’ organelles were noted as a less significant feature of the injury.
• The research suggests that mechanisms leading to early fluid accumulation under the epithelial layer are important, rather than direct severe injury to the enterocytes or migration from the luminal surface.
• A vigorous retraction mechanism in the villus seemed to amplify the epithelial damage towards the villus tip. A possible reason for this could be a particular “pathomechanical effect.”

Implications of the Study

• The findings of this research provide valuable insights into the negative effects of ischemia and reperfusion on the equine jejunum.
• It also sheds light on the protective role DMSO could potentially play in preventing jejunal injury.
• The results could be particularly relevant to veterinary medicine, potentially leading to better preventive strategies and treatments for intestinal damage in horses.