Determination of blood levels of intracellular enzymes is an appropriate method to evaluate tissue and organ damage. To show systemic tissue damage resulting from intestinal ischemia-reperfusion, New Zealand rabbits underwent 60 min intestinal ischemia and 60 min reperfusion. Plasma samples were obtained before and at 55, 70, and 120 min after operation and enzyme levels were determined. Plasma aspartate aminotransferase (AST) showed a significant increase during reperfusion while lactate dehydrogenase (LDH) and creatine kinase (CK) levels were significantly increased at the end of ischemia and continued to be so throughout reperfusion. It is difficult to claim that enzymes arise from the intestine, but an increase of CK, LDH, and later of AST without any increase in alanine aminotransferase levels during ischemia suggests that their primary source is the injured intestine. Increased levels of plasma enzymes do not provide exact information about the location, but do reveal the presence of an injury.