Arteriovenous differences for glutamine in the equine gastrointestinal tract.

The study focuses on determining the importance of glutamine, a metabolic substrate, in the metabolism of cells of the equine gastrointestinal tract. This is achieved by analyzing arterial and venous variations in glutamine concentrations in the intestines of horses and measuring the activity of glutaminase, the enzyme responsible for breaking down glutamine.

Metabolic Importance of Glutamine

• The research involves understanding glutamine’s metabolic significance in the cells of a horse’s gastrointestinal tract. Glutamine has been proven to be a vital metabolic substrate of enterocytes in several animals, which implies it plays a role in energy provision, anabolism, and cell signaling in these enterocytes (intestinal cells).

Transintestinal Differences in Glutamine Concentrations

• The study observed variations in glutamine concentrations in the arterial and venous circulation. This entails examining the differences in glutamine levels between the blood coming into the intestine (arterial) and going out (venous). Such differences provide an approximation of how much substrate is consumed by the intestinal tissue.

Glutamine Extraction

• Glutamine extraction was measured in seven anesthetized adult horses, both before and after administering a glutamine infusion. Baseline extraction by the portal-drained viscera increased dramatically immediately after the infusion, but returned to baseline levels after 60 minutes.
• The arteriovenous differences were more significant across the jejunum, indicating that this part of the intestine used glutamine more efficiently than others.

Glutaminase Activity

• The activity of glutaminase, the enzyme that breaks down glutamine, was also measured. It maintained a standard level in both the jejunal and ileal mucosa. This measurement is crucial as the activity of this enzyme directly relates to the rate of glutamine metabolism.
• The experiment yielded essential insights about how the equine gastrointestinal tract metabolizes glutamine and which regions utilize it more efficiently, contributing to our knowledge and potential for further research in the field of veterinary science and animal nutrition.