Effects of ischemia and dimethyl sulfoxide on equine jejunal vascular resistance, oxygen consumption, intraluminal pressure, and potassium loss.

The research investigates the physiological effects of ischemia on horse intestine – particularly the equine jejunum. It also evaluated the protective impacts of the compound dimethyl sulfoxide (DMSO) on the jejunum during ischemia and reperfusion, with the study conducted on a sample of 18 ponies.

Research Design and Groups

• The study used 18 ponies and divided them into four groups. The divisions allowed for controlled and variable experiments, where ischemia was induced in half of the groups and DMSO administered to the other half.
• Group 1 was the control group administered saline solution; Group 2 received only DMSO; Group 3 had ischemia induced, followed by saline administration; Group 4 had ischemia induced, followed by DMSO administration.
• The equine jejunum was studied using neurally intact segments perfused at constant flow with heparinized blood. This meant that the blood was treated to prevent clotting, ensuring the smooth flow in the experiment device.

Parameters and Variables

• The parameters observed during the experiment included intestinal vascular resistance, oxygen consumption, the frequency and amplitude of rhythmic changes in intraluminal pressure, intestinal compliance, and arteriovenous potassium concentration difference.
• These variables were measured and compared before and after the induction of ischemia and during the reperfusion phase, for both ischemic and non-ischemic sections.

Results

• Results showed that there were no significant changes in groups 1 and 2, meaning that saline and DMSO administration without ischemia did not affect the observed parameters.
• In group 3, ischemia significantly affected all the variables, resulting in an increase in vascular resistance during reperfusion, decrease in oxygen consumption during reperfusion, and changes in rhythmic contractions along with an increase in potassium concentration during reperfusion.
• In group 4, ischemia-induced changes were similar to group 3, but DMSO administration prevented the decrease in vascular resistance during reperfusion, indicating a protective effect on the equine jejunum during the recovery from ischemia.

This study provided insights into the physiology of equine intestine during conditions of limited blood supply and the potential therapeutic benefits of DMSO in managing such conditions.