Sphingosine-1-phosphate and its analogue FTY720 diminish acute pulmonary injury in rats with acute necrotizing pancreatitis

Objective: To investigate the effects of sphingosine-1-phosphate (S1P) and its analogue FTY720 on the lung injury induced by acute necrotizing pancreatitis in rats. Methods: Acute necrotizing pancreatitis was induced by retrogradely injection of 5% sodium taurocholate of biliopancreatic duct in rats. Sphingosine-1-phosphate (100 mu g/kg) or FTY720 (1 mg/kg) was administered immediately after the model induction by peritoneal injection. Six hours after the model induction, bronchoalveolar lavage protein concentration, total cell count, polymorphonuclear neutrophil percentage, proinflammatory cytokines (interleukin 1 beta, interleukin 6, and tumor necrosis factor alpha), nuclear factor kappa B activation of alveolar macrophages, and lung myeloperoxidase (MPO) activity were examined. Serum amylase and lipase were tested. In addition, histopathological changes of the pancreas and lung were observed. Results: Bronchoalveolar lavage protein concentration, total cell count, PMN percentage, proinflammatory cytokines, nuclear factor kappa B activation, lung capillary leakage, and lung myeloperoxidase were all reduced significantly in both S1P and FTY720 groups. The pulmonary pathological injury in both S1P and FTY720 groups was ameliorated obviously. Nevertheless, the serum amylase, lipase, and the pancreatic pathological damages were not decreased. Conclusions: Sphingosine-1-phosphate and its analogue FTY720 significantly decreased pulmonary inflammation and injury in a rat model of acute lung injury caused by acute necrotizing pancreatitis and may represent a novel therapeutic strategy for the acute necrotizing pancreatitis-associated lung injury.