Morphologic effects of experimental distention of equine small intestine.

The study investigates the changes in the morphology or structure of isolated horse small intestine segments, under induced internal pressures. The result showed swelling and cell separation in the tissue, but no significant cell death after the test duration.

Research Methodology

• The research was conducted on 33 detached segments of a horse’s jejunum – a part of the small intestine.
• The experimental design involved inducing varying levels of internal hydrostatic pressures (IHPs) – 0, 9, and 18 cm of water.
• Fifteen segments were expanded with Tyrode’s solution, an aqueous electrolytic solution mimicking body fluids, for 1 hour, and another nine segments were treated similarly for 4 hours.
• The solution was added as required to keep the set pressures.
• After the initial expansion period, nine other segments were left undisturbed for 4 hours.

Research Findings

• When the pressure was released from the small intestine segments, they all resumed to normal peristaltic contractions – the wave-like muscle movements for food digestion.
• Microscoping these intestinal sections using light microscopy and transmission electron microscopy revealed tissue swelling in the villi, tiny lining projections in the intestine enhancing absorption, and the submucosa layer beneath it.
• The above observation was coupled with some separation between epithelial cells (outer tissue layer cells) and the basement membrane, their underlying layer.
• Interestingly, they did not observe epithelial cell necrosis, tissue death due to the insufficient blood supply typically found in ischemic intestine, the condition where blood flow to the intestine is blocked.
• Therefore, the researchers concluded that the tissue death commonly seen at the villous tips in expanded small intestine sections, distant from the blockage site, couldn’t be replicated by just increasing IHP for up to 4 hours.