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This work studied the activation of hepatic macrophages during acute pancreatitis and the involvement of these cells in the lung inflammatory response. Pancreatitis was induced in Wistar rats by intraductal administration of 5% sodium taurocholate. Three hours after pancreatitis induction, the degree of pulmonary inflammation, TNF-α levels, and P-selectin expression were evaluated. The generation of TNF-α by Kupffer cells was also measured. Pancreatitis increases the serum concentration of TNF-α, neutrophil infiltration, and P-selectin expression in pancreas and lung. In addition, Kupffer cells generate increased levels of TNF-α. When Kupffer cells were inhibited, the increase in serum TNF-α levels and the infiltration of neutrophils in the lung were prevented, but P-selectin expression remained unmodified. We conclude that pulmonary inflammation induced by acute pancreatitis is mediated by Kupffer cell activation and that pancreatitis induces the expression of P-selectin on pulmonary endothelial cells but this effect is not mediated by Kupffer cells.

Formation of nitric oxide (NO) inischemia-reperfusion (I-R) associated with pancreastransplantation could modulate the inflammatoryresponse. In this sense, previous studies havedemonstrated the action of NO on vasoactive substances likeprostacyclin or endothelin. The present study wasdesigned to evaluate the contribution of endothelin tothe inflammatory events induced by NO in the I-R processassociated with pancreas transplantation. For thispurpose, pancreatic levels of endothelin, neutrophilinfiltration, and prostacyclin were evaluated in anexperimental model of pancreas transplantation afterinhibition of NO synthesis or after NO inhibition plusaddition of endothelin. Results show significantposttransplantation increases in endothelin, neutrophilinfiltration, and prostacyclin production. Theseincreases were prevented by NO inhibition. Endothelinadministration plus nitric oxide inhibition reversedthis effect, resulting in an increase in myeloperoxidaseand 6-ketoprostaglandin F1α. Theseresults suggest that the proinflammatory effects of NO in I-Rassociated with pancreas transplantation are mediated bythe induction of endothelin generation.

The role of nitric oxide, produced during reperfusion as a function of preservation time, in the development of the inflammatory process in pancreas transplantation has been explored. For this purpose, the effect of nitric oxide synthase inhibition, as well as 6-keto-prostaglandin F1alpha, leukotriene B4, and lipoperoxidation levels were evaluated in an experimental model of rat pancreas transplantation after different periods of cold preservation. The results show posttransplantation increases in 6-keto-prostaglandin F1alpha, leukotriene B4, and lipoperoxidation levels in pancreatic tissue and in plasma lipase. When ischemia was induced for 30 min, nitric oxide synthase inhibition prevented these increases, and L-arginine was able to reverse this effect. By contrast, nitric oxide synthase inhibition has no effect when ischemia was prolonged for 12 hr. In summary, this study suggests that, during reperfusion, nitric oxide modulates 6-keto-prostaglandin F1alpha synthesis, lipoperoxidation levels, and the development of pancreatic injury but only when the ischemic period is quite short.

Systemic prostacyclin and thromboxane A2 production in rat experimental acute pancreatitis has been evaluated by measuring the urinary excretion of the 2,3-dinor 6-keto prostaglandin F1 alpha and 2,3-dinor thromboxane B2, respectively. Acute pancreatitis was induced by intraductal administration of 4.5% sodium taurocholate (0.1 ml/100 mg body weight) and intravenous cerulein perfusion (5 micrograms/kg/hr) for 6 hr, respectively. Urinary excretion of 2,3-dinor 6-keto prostaglandin F1 alpha and 2,3-dinor thromboxane B2 were much more important in sodium taurocholate- than in cerulein-induced acute pancreatitis. These data confirm an altered prostacyclin and thromboxane metabolism occurring in experimental acute pancreatitis. Phospholipase A2 activity and the effect of gabexate mesilate on the arachidonate metabolism were also evaluated.

This work studied the activation of hepatic macrophages during acute pancreatitis and the involvement of these cells in the lung inflammatory response. Pancreatitis was induced in Wistar rats by intraductal administration of 5% sodium taurocholate. Three hours after pancreatitis induction, the degree of pulmonary inflammation, TNF-alpha levels, and P-selectin expression were evaluated. The generation of TNF-alpha by Kupffer cells was also measured. Pancreatitis increases the serum concentration of TNF-alpha, neutrophil infiltration, and P-selectin expression in pancreas and lung. In addition, Kupffer cells generate increased levels of TNF-alpha. When Kupffer cells were inhibited, the increase in serum TNF-alpha levels and the infiltration of neutrophils in the lung were prevented, but P-selectin expression remained unmodified. We conclude that pulmonary inflammation induced by acute pancreatitis is mediated by Kupffer cell activation and that pancreatitis induces the expression of P-selectin on pulmonary endothelial cells but this effect is not mediated by Kupffer cells.

Formation of nitric oxide (NO) in ischemia-reperfusion (I-R) associated with pancreas transplantation could modulate the inflammatory response. In this sense, previous studies have demonstrated the action of NO on vasoactive substances like prostacyclin or endothelin. The present study was designed to evaluate the contribution of endothelin to the inflammatory events induced by NO in the I-R process associated with pancreas transplantation. For this purpose, pancreatic levels of endothelin, neutrophil infiltration, and prostacyclin were evaluated in an experimental model of pancreas transplantation after inhibition of NO synthesis or after NO inhibition plus addition of endothelin. Results show significant posttransplantation increases in endothelin, neutrophil infiltration, and prostacyclin production. These increases were prevented by NO inhibition. Endothelin administration plus nitric oxide inhibition reversed this effect, resulting in an increase in myeloperoxidase and 6-keto-prostaglandin F1alpha. These results suggest that the proinflammatory effects of NO in I-R associated with pancreas transplantation are mediated by the induction of endothelin generation.

The role of nitric oxide, produced during reperfusion as a function of preservation time, in the development of the inflammatory process in pancreas transplantation has been explored. For this purpose, the effect of nitric oxide synthase inhibition, as well as 6-keto-prostaglandin F1alpha, leukotriene B4, and lipoperoxidation levels were evaluated in an experimental model of rat pancreas transplantation after different periods of cold preservation. The results show posttransplantation increases in 6-keto-prostaglandin F1alpha, leukotriene B4, and lipoperoxidation levels in pancreatic tissue and in plasma lipase. When ischemia was induced for 30 min, nitric oxide synthase inhibition prevented these increases, and L-arginine was able to reverse this effect. By contrast, nitric oxide synthase inhibition has no effect when ischemia was prolonged for 12 hr. In summary, this study suggests that, during reperfusion, nitric oxide modulates 6-keto-prostaglandin F1alpha synthesis, lipoperoxidation levels, and the development of pancreatic injury but only when the ischemic period is quite short.

The role of nitric oxide, produced during reperfusion as a function of preservation time, in the development of the inflammatory process in pancreas transplantation has been explored. For this purpose, the effect of nitric oxide synthase inhibition, as well as 6-keto-prostaglandin F(1α) leukotriene B4, and lipoperoxidation levels were evaluated in an experimental model of rat pancreas transplantation after different periods of cold preservation. The results show posttransplantation increases in 6-keto-prostaglandin F(1α), leukotriene B4, and lipoperoxidation levels in pancreatic tissue and in plasma lipase. When ischemia was induced for 30 min, nitric oxide synthase inhibition prevented these increases, and L-arginine was able to reverse this effect. By contrast, nitric oxide synthase inhibition has no effect when ischemia was prolonged for 12 hr. In summary, this study suggests that, during reperfusion, nitric oxide modulates 6-keto-prostaglandin F(1α) synthesis, lipoperoxidation levels, and the development of pancreatic injury but only when the ischemic period is quite short., This work was supported by grant 94/0645, Fondo de Investigaciones Sanitarias and by grant B.A.E. Fiss 94/5047

The aim of this work is to establish a relationship between prostanoids and oxygen free radicals in the early stages of acute pancreatitis induced by sodium taurocholate and to study the possible cytoprotective effects of exogenous prostaglandin administration. Tissue prostanoid production (6-keto-prostaglandin F1 alpha, thromboxane B2, and prostaglandin E2) was studied after induction of an acute pancreatitis by intraductal administration of 3.5% sodium taurocholate (0.1 ml/100 mg). The effect of previous administrations of 16,16-dimethyl prostaglandin E2 (0.5 microgram/kg), indomethacin (20 mg/kg), or superoxide dismutase (13 mg/kg) was evaluated. Early pancreatitis induced significant increases of the three prostanoid levels as soon as 5 min after taurocholate administration. The administration of 16,16-dimethyl prostaglandin E2 was able to maintain the tissue prostanoid production at basal levels while superoxide dismutase treatment only partially prevented the increase of 6-keto-prostaglandin F1 alpha. On the other hand, indomethacin pretreatment, as expected, prevented the taurocholate-induced early prostanoid biosynthesis but increased the mortality, suggesting that endogenous prostanoids play a role in cellular defense mechanisms. The effect of superoxide dismutase suggests that oxygen free radicals are responsible, in part, for prostanoid enhanced biosynthesis in the earlier stages of necrohemorrhagic pancreatitis.