Effects of superoxide dismutase on injury induced by anoxia and reoxygenation in equine small intestine in vitro.

The study investigates the effects of superoxide dismutase on tissue damage caused by lack of oxygen and subsequent reoxygenation in horse’s small intestine.

Methodology

• The researchers used sheets of mucosa from the jejunum (a part of the small intestine) of healthy horses.
• These samples were placed in incubation chambers and soaked in a solution called Krebs-Ringer bicarbonate.
• They tested several conditions: the control condition with constant oxygen, the same condition with superoxide dismutase added towards the end, one with a period of anoxia (lack of oxygen) followed by reoxygenation, the same with superoxide dismutase added during reoxygenation, and finally a condition with a longer period of anoxia.

Findings

• Anoxia led to lower levels of radiolabeled L-alanine a radioactively marked molecule) and cellular swelling, indicated by increased tissue water and tissue Na contents.
• Reoxygenation improved the accumulation of L-alanine but didn’t stop the tissue swelling.
• On application of superoxide dismutase during reoxygenation, tissue Na content and L-alanine accumulation went back to control state indicating improvement.
• Morphological damage (separation of epithelial cells from villi) was severe in all cases except the control conditions.
• Superoxide dismutase had no effect on the tissue under control conditions.

Conclusions

• The study suggests that superoxide radicals, which superoxide dismutase deals with, play a role in the damage caused to equine jejunal mucosa during reperfusion (reintroduction of oxygen).
• This could be clinically relevant in addressing conditions like small intestinal strangulation.