Direct ESR measurement of free radicals in mouse pancreatic lesions.

In this experiment, free radicals in the pancreas of endotoxemia and ethionine induced acute pancreatitis in mice were attempted to be detected directly by ESR spectroscopy, using 77 K freeze-trapping and 25 degrees C DMPO spin trapping techniques. In the 77 K freeze-trapping method, Mn (II) ion and R-00. radical were detected in endotoxemia and ethionine induced pancreatic lesions. The heme-NO radical was observed at 6 and 24 h after isolation of the normal pancreas, and signal intensity was increased with time. This finding supports that ESR spectroscopy is a useful method for detecting the tissue degeneration process from ischemia to necrosis. Using the DMPO spin trapping technique (25 degrees C), 6-line was detected at 6 h after intraperitoneal administration of E. coli in the model of endotoxemia, and 3- and 6-lines and a signal suggestive of DMPO-OH adduct were noted at 12 and 24 h in ethionine pancreatitis. These findings suggest that impaired pancreatic tissues exist in a considerably oxidative environment and oxygen derived free radicals may be considered to play an important role in the development of pancreatic lesions.