Reperfusion injury in the equine large colon

Karin Marina Kooreman, Purdue University

Abstract

The purpose of the study was to confirm or refute the presence of free oxygen radicals during reperfusion of ischemic equine large colon with oxygenated blood. Three groups of six horses were studied in a terminal procedure under general anesthesia. In Group I and III tissue samples were taken from affected and normal colon during ischemia (105 minutes) and at 10, 30, 60 and 120 minutes post reperfusion with oxygenated blood. In Group I, 2 hours of ischemia was achieved by placement of Rommel ligatures around the colonic arteries and veins, creation of a 360$\sp\circ$ torsion of the large colon and luminal inflation to a pressure of 25 cm H$\sb2$O with the colon replaced in the abdomen. Malondialdehyde, an indicator of lipid peroxidation, was not demonstrated in ischemic, reperfused or normal large colon. In Groups II and III a transection of the colon was performed in addition to Rommel ligatures placed around the colonic arteries and veins. In Group II, after 5 minutes of reperfusion the affected colon was perfused with 40 mmol/l manganese citrate, followed by 2.5 mmol/l diaminobenzidine. Polymerized DAB as an indicator of superoxide production was not found in the large colon. In Group III, conjugated dienes were determined during ischemia (105 minutes), and at 10, 30, 60 and 120 minutes of reperfusion. No significant changes in conjugated diene levels were found. In conclusion, reactive oxygen species do not play a significant role in equine colonic reperfusion injury after two hours of ischemia. These findings are in contrast to equine jejunum undergoing two hours of ischemia and subsequent reperfusion, as in the jejunum significant amounts of malondialdehyde and conjugated dienes were found and superoxide activity was demonstrated by the presence of diaminobenzidine.

Degree

Ph.D.

Advisors

Lamar, Purdue University.

Subject Area

Veterinary services|Anatomy & physiology|Surgery

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