Time course of lung injury in rat acute pancreatitis

Abstract

Objective: Lung injury is a severe complication of acute pancreatitis that increases the mortality rate of the disease. The pathophysiology of acute pancreatitis has been studied in several experimental models, but the kinetics of pulmonary complications in relation to the pancreatic disease is not completely understood. We then studied the severity of acute pancreatitis-associated lung injury over 18h in rats that had taurocholic acid injection in the pancreatic duct and determined whether blood collected from rats with pancreatitis is toxic enough to induce injury in normal lungs.

Design and setting: Prospective, randomized, and controlled animal study in an animal research laboratory in a university hospital.

Interventions: We isolated lungs from rats with acute pancreatitis 2, 6, and 18h after taurocholic acid injection in the biliopancreatic duct and perfused them with blood collected from the same rats. Additionally, blood collected from rats with acute pancreatitis (time-points: 2 and 6h) was perfused in normal lungs.

Measurements and results: Taurocholic acid injection induced a severe pancreatic injury that started as early as 2h after the injection and persisted without recovery over the 18-h study period. In contrast, the pulmonary injury was transient, appearing at the 6-h time point with recovery by the end of the study. Pulmonary injury was moderate and evidenced mostly during lung reperfusion. Interestingly, blood collected at the 2-h time point in pancreatic rats induced pulmonary injury in normal lungs while blood collected at the 6-h time-point was not toxic.

Conclusions: While pancreatic injury persists over the full experimental period, pulmonary injury is transient in our experimental model. The recovery of lung injury by 18h might be explained by a decrease in the overall toxicity of pancreatic blood over time.