[Expression of heme oxygenase-1 in ischemic colitis]

Ischemic colitis is a vascular condition of inadequate blood flow in the colon which leads to colonic inflammation and can cause significant morbidity and mortality. Oxidative stress is an early initiating event in ischemia and reperfusion injury. Heme oxygenase (HO) is considered to be an antioxidant enzyme that catabolizes heme to carbon monoxide, free iron and biliverdin. The aim of this study was to evaluate the expression patterns of HO-1, inducible form of HO, in ischemic colitis.

We analyzed the twelve cases of clinically and pathologically diagnosed ischemic colitis without surgical intervention compared with normal colon (n=10) and psedomembranous colitis (n=5). Immunohistochemical stainings for HO-1 were performed in paraffin-embedded tissues.

The age of the patients ranged from 56 to 84 years (mean: 67 years) in ischemic colitis. Eight patients (66.7%) were female. The most common presenting symptom was bloody stool (66.7%) and rectosigmoid area (91.7%) of the large intestine was the most common ischemic site. Expression of HO-1 in ischemic colitis was high in contrast to normal colonic mucosa or psedomembranous colitis.

Ischemic colitis usually involves the rectosigmoid area in elderly female patients with a history of bloody stool. High expression of HO-1 in ischemic colitis may be responsible for a protective mechanism to ischemia or heme injury.