Electromyographic, myomechanical, and intraluminal pressure changes associated with acute extraluminal obstruction of the jejunum in conscious ponies.

This research examined the changes in muscle electrical activity, muscle mechanics, and internal pressure in the jejunum (part of the small intestine) of ponies when an obstruction was artificially induced. It found that muscle activity increased above the obstruction point, while it remained the same below. The increase in pressure was observed during periods of intestinal contractions, but remained the same before and after the obstruction.

Experimental Setup

• The researchers used a variety of tools to conduct this study. Bipolar electrodes, strain gauge force transducers, intraluminal pressure recording catheters, and extraluminal intestinal obstructors were surgically implanted in four ponies.
• The implanted tools allowed them to record the electrical and mechanical activities in the lower part of the ponies’ jejunum and their ileum (the last part of the small intestine).
• The focus of the study was mainly on the changes that occur when the jejunum is obstructed.

Findings and Conclusions

• After determining the normal intestinal activities and pressures without any obstruction, the researchers introduced an obstruction in the lower part of the jejunum using the surgically implanted obstructor.
• The data recorded from this setup showed a significant increase (P < 0.01) in both the electrical and mechanical activities in the sections of the jejunum that are situated before (above) the obstruction point.
• On the other hand, the parts of the jejunum located after (below) the obstruction point did not show any noticeable change in their activity levels.
• In addition to these, the internal pressure of the jejunum also showed some fluctuations. Notable increases in this pressure were only recorded during the periods when intestinal spasms were occurring.
• Interestingly, the pressures recorded at the obstruction points didn’t themselves change from what was recorded when there was no obstruction present.
• Overall, the findings of this study could prove useful in understanding and predicting how the body reacts to different types of intestinal obstructions, specifically in the lower part of the jejunum in horses.