Role of oxygen-derived free radicals in superior mesenteric artery occlusion shock in rats

This study was designed to investigate effects of cellular injury mediated by oxygen-derived free radicals on the intestine, heart, liver, kidney and lung tissues during superior mesenteric artery occlusion shock in rats. The animals were divided into four groups: control (Group 1, n = 6), one hour occlusion (Group 2, n = 8), one hour after releasing the clamp (Group 3, n = 8), and two hours after releasing the clamp (Group 4, n = 8). Compared to control values, the contents of malondialdehyde (MDA) in each tissue in Group 2 had 110 significant changes (P greater than 0.05); in Group 3, MDA in the intestine and heart tissues significantly elevated by 62% (P less than 0.05) and 56% (P less than 0.05); in Group 4, MDA in the intestine, heart, liver, and lung tissues increased by 121% (P less than 0.01), 65% (P less than 0.05), 32% (P less than 0.05), and 31% (P less than 0.05), respectively. Plasma lactic acid, beta-glucuronidase and acid phosphatase increased significantly (P less than 0.01). The results showed that oxygen-derived free radical could cause lipid peroxidation damage not only in the intestine tissue, but also in the heart, liver, and lung tissues, suggesting that oxygen-derived free radicals might play an important role in cellular injury during superior mesenteric artery occlusion shock.