Inosine alleviates rat caerulein pancreatitis and pancreatitis-associated lung injury

Background. Recent studies have shown that inosine, a purine nucleoside produced during the breakdown of adenosine, has immunomodulatory and anti-inflammatory properties. The aim of this study was to examine the effects of inosine on the course of acute pancreatitis. Methods. Edematous pancreatitis was induced by the intraperitoneal injection of caerulein (50μg/kg), seven times, at 1-h intervals, in male Wistar rats (caerulein pancreatitis). Inosine (100mg/kg) was administered 30 min before or 1 h after the first injection of caerulein. The effects of inosine on the severity of pancreatitis were assessed by serum amylase, pancreatic edema (wet/dry ratio), myeloperoxidase activity, cytokine-induced neutrophil chemoattractant-1 concentrations, and histological changes. Results. Prophylactic administration of inosine significantly decreased the elevation of serum amylase, myeloperoxidase activity, and cytokine-induced neutrophil chemoattractant-1 concentrations in the pancreas and the lung. Inosine did not significantly affect edema formation. Histologically, vacuole formation in pancreatic acinar cells, infiltration of inflammatory cells in the pancreas and the lung, and alveolar wall thickening in the lung were reduced. Inosine improved the histological findings and reduced myeloperoxidase activity even if it was administered 1 h after the first injection of caerulein. Conclusions. Inosine reduced the severity of acute pancreatitis, suggesting a possible application of this compound in the treatment of acute pancreatitis.