Peroxynitrite decomposition catalyst FeTMPyP provides partial protection against intestinal ischemia and reperfusion injury in infant rats.

Free radicals are important in development of intestinal ischemia-reperfusion (I/R) injury, leading to intestinal and pulmonary damage. We evaluated the effects of peroxynitrite decomposition catalyst FeTMPyP in infant intestinal I/R. Suckling rats underwent 40 min intestinal ischemia + 90 min reperfusion. At reperfusion, animals received saline or FeTMPyP. Groups were (n = 11 per group): 1) control+saline; 2) I/R+saline; 3) I/R+FeTMPyP. Increased histologic injury and ICAM-1 expression were observed in ileum of both I/R+saline and I/R+FeTMPyP rats, but P-selectin expression was increased in I/R+saline animals only versus controls. Myeloperoxidase (neutrophil infiltration marker) was increased in ileum and lungs of I/R+saline rats, but FeTMPyP prevented this in the ileum. I/R+saline animals showed higher malondialdehyde (lipid peroxidation marker) in ileum and lungs versus both control+saline and I/R+FeTMPyP rats. Glutathione was decreased in all I/R animals, but oxidized and total glutathione were higher in I/R+FeTMPyP than the I/R+saline group. Nitrate+nitrite concentration (systemic nitric oxide production) was elevated in I/R+saline but not in I/R+FeTMPyP animals. FeTMPyP provides limited protection against intestinal I/R in neonatal rats by reducing ileal P-selectin expression, systemic nitric oxide production, neutrophil infiltration in ileum and lipid peroxidation in both lungs and ileum; and preserving intestinal antioxidant capacity.