Effect of large colon ischemia and reperfusion on concentrations of calprotectin and other clinicopathologic variables in jugular and colonic venous blood in horses.

The study investigates how large colon ischemia and reperfusion in horses impact the concentration of the inflammatory protein calprotectin and other clinical and pathological variables in the blood from both the jugular and colonic veins.

Objective and Methods of the study

• In this study, an attempt was made to understand the effects of large colon ischemia (restricted blood supply) and the subsequent reperfusion (restoration of the blood supply) on the levels of calprotectin, a protein marker of inflammation produced by neutrophils, and other clinicopathologic variables in the jugular and colonic venous blood of horses.
• The study was conducted on six healthy horses which were anesthetized, following which the blood supply to a part of the large colon was obstructed for an hour. This process created the desired ischemia. It was followed by a 4-hour long reperfusion, allowing blood to flow back into the obstructed section.
• Blood samples were collected at different intervals before anesthetization, before inducing ischemia, an hour into the ischemia, and at 1, 2, and 4 hours into the reperfusion. These blood samples were collected from the jugular vein as well as colonic veins connected to the affected part of the large colon.

Key Results

• Ischemia of the large colon led to metabolic acidosis, a marked increase in lactate and potassium concentrations, and the activity of creatine kinase. It was also noted a nonsignificant drop in glucose concentrations in colonic venous blood samples. After reperfusion, these variable values returned to pre-ischemia levels.
• Ischemia and the subsequent reperfusion triggered an inflammatory response, shown by increased neutrophil cell turnover rates in both jugular and colonic venous blood samples. The colonic venous blood samples also showed increased calprotectin levels, strengthening the evidence of inflammation.

Study Conclusion

• The results of the study suggested that large colon ischemia and reperfusion caused localized and systemic inflammation in horses. The study also postulates that monitoring serum calprotectin concentration could be a useful marker for this inflammatory response.