The involvement of oxygen radicals in acute pancreatitis

The purpose of this study was to assess the involvement of oxygen radicals in acute edematous and hemorrhagic panreatitis. Acute pancreatitis was induced in rats by the CCK-analogue cerulein (5 μg/kg/h) and by retrograde injection of 5% sodium taurocholate for 30 min, 3.5 h, and 12 h. At the end of the infusion and observation time, serum enzymes, conjugated dienes, and malondialdehyde in the tissue were measured. Moreover, the tissue samples underwent light microscopical examination. In cerulein pancreatitis, an interstitial edema and intravascular margination of granulocytes in the pancreatic gland were observed after 3.5 h. After 12 h, the histological evaluation revealed a pronounced zymogen degranulation, extensive tissue necrosis and migration of granulocytes into the tissue. Parallelly, amylase and lipase increased by 15 and 35 times, respectively. In contrast, conjugated dienes and malondialdehyde increased in cerulein pancreatitis and reached their highest level after 3.5 h and decreased to normal levels after 12 h. The development of the histological damages and serum enzyme levels with sodium taurocholate pancreatitis was similar as compared to the cerulein pancreatitis, however, the development was faster and more traumatic. Already after 3.5 h an extensive zymogen degranulation and cell necrosis was observed. Concomitantly, the amylase and lipase levels increased by 90 and 30 times, respectively. Treatment with superoxide dismutase (100000 U/kg/h) and catalase (400 000 U/kg/h) prevented lipid peroxidation and reduced zymogen degranulation and tissue necrosis. Tissue edema and inflammatory response were not affected in both models of acute pancreatitis. Moreover, scavenger treatment improved the survival rate in sodium taurocholate pancreatitis. It is therefore concluded that oxygen free radicals seem to be instrumental for the development of the disease. Scavenger treatment can mitigate the pancreatic tissue damages and the extrapancreatic complications.