Remote lung injury after experimental intestinal ischemia-reperfusion in horses.

This research explores the damaging effects on lung tissue after intestinal obstruction in horses and the mitigating effects of lidocaine. Intestinal obstructions lead to a release of harmful molecules into the bloodstream, causing damage to remote organs like the lungs.

Experiment and Findings

• The researchers conducted an experiment on horses experiencing intestinal ischemia-reperfusion(IR), a condition occurring from intestinal obstruction. After a certain period of oxygen deprivation (ischemia) and subsequent restoration (reperfusion), toxic molecules are released, potentially damaging other organs. In the experiment, lung tissues were collected from the control group of anesthetized and non-anesthetized horses (n=8) and those undergoing IR (n=12).
• Researchers noted an accumulation of neutrophils, a type of white blood cells, in the lungs of IR affected horses. This accumulation triggers an immune response in the lungs and couldn’t be observed in the control group.
• Increased presence of TLR4, IL-8, TLR9 and von Willebrand factor (vWF) were observed in the lungs of horses affected by IR. These are proteins and factors involved in immune and inflammatory responses, their presence indicates an active immune response likely due to injury caused by IR.
• Lung TNFα, a protein involved in systemic inflammation, was significantly increased in IR horses compared to control horses.
• The conclusion was that intestinal ischemia-reperfusion does lead to lung injury in horses characterized by the recruitment of inflammatory cells and the expression of inflammatory molecules.

Lidocaine’s Effect

• An aspect of the experiment dedicates the use of lidocaine, a local anesthetic and antiarrhythmic drug, to determine its effect on this lung inflammation.
• The horses under IR conditions were divided into two groups, one receiving Lactated Ringer’s Solution (n=6) and the other lidocaine (n=6) intravenously.
• The neutrophil counts were significantly lower and macrophage numbers higher in horses receiving lidocaine as compared to the LRS horses. Macrophages play a key role in fighting infections and inflammation.
• Based on these findings, the study concludes that lidocaine may ameliorate, i.e., make better, the lung inflammation following intestinal ischemia-reperfusion in horses.