Blockade of endotoxin-induced cecal hypoperfusion and ileus with an alpha 2 antagonist in horses.

The research paper investigates whether blocking alpha 2 adrenergic receptors could restore normal gut function and blood flow during endotoxemia in horses. Results showed that application of a certain substance diminished the detrimental effects of endotoxemia, suggesting that these negative impacts indeed involve alpha 2 adrenergic receptors.

Objective and Purpose of the Research

• The primary aim of this study was to discover if blocking alpha 2 adrenergic receptors can restore normal cecal motility (a part of the large intestine) and blood flow during endotoxemia in horses. Endotoxemia is a condition characterized by the presence of endotoxins (toxins present inside bacterial cells) in the blood, which causes a severe immune response.

Methodology and Experimentation

• The researchers made use of strain-gauge force transducer and ultrasonic flow probes to monitor cecal and colonic activity, and blood flow in the lateral cecal artery.
• The team induced endotoxemia in the subject horses via intravenous infusion. This process showed significant decreases in cecal and right ventral colon contractile activity, as well as in lateral cecal arterial blood flow.
• The team then used slow intravenous infusion of yohimbine to block the alpha 2 adrenergic receptors and observed the effects on the impacted areas.
• Yohimbine significantly attenuated the effects of endotoxin. This indicated that the negative impacts of endotoxemia involved alpha 2 adrenergic receptors.

Findings and Conclusion

• The study found that endotoxemia caused cecal and proximal colonic ileus (disruption of the normal propulsive gastrointestinal activity) and cecal hypoperfusion (decreased blood flow)
• The findings suggested that these phenomena occur as a result of a mechanism that involves alpha 2 adrenergic receptors, given the fact that blocking these receptors with yohimbine significantly mitigated the conditions.
• Thus, the researchers concluded that the using an alpha 2 antagonist could be a potential therapeutic approach for treating endotoxemia-associated complications in horses.