AIM： To investigate the role of oxidative injury in pancreatitis-induced hepatic damage and the effect of antioxidant agents such as melatonin, ascorbic acid and N-acetyl cysteine on caerulein-induced pancreatitis an...AIM： To investigate the role of oxidative injury in pancreatitis-induced hepatic damage and the effect of antioxidant agents such as melatonin, ascorbic acid and N-acetyl cysteine on caerulein-induced pancreatitis and associated liver injury in rats. METHODS： Thirty-eight female Wistar rats were used. Acute pancreatitis （AP） was induced by two i.p. injections of caerulein at 2-h intervals （at a total dose of 100 μg/kg b.wt）. The other two groups received additional melatonin （20 mg/kg b.wt） or an antioxidant mixture containing L（＋）-ascorbic acid （14.3 mg/kb.wt.） and N-acetyl cysteine （181 mg/kg b.wt.） i.p. shortly before each injection of caerulein. The rats were sacrificed by decapitation 12 h after the last injection of caerulein. Pancreatic and hepatic oxidative stress markers were evaluated by changes in the amount of lipid peroxides measured as malondialdehyde （MDA） and changes in tissue antioxidant enzyme levels, catalase （CAT） and glutathione peroxidase （GPx）. Histopathological examination was performed using scoring systems. RESULTS： The degree of hepatic cell degeneration, intracellular vacuolization, vascular congestion, sinusoidal dilatation and inflammatory infiltration showed a significant difference between caerulein and caerulein＋melatonin （P= 0.001）, and careulein and caerulein ＋ L（＋）- ascorbic acid ＋N-acetyl cysteine groups （P= 0.002）. The degree of aciner cell degeneration, pancreatic edema, intracellular vacuolization and inflammatory infiltration showed a significant difference between caerulein and caerulein ＋ melatonin （P=0.004）, and careulein and caerulein ＋ L（＋）-ascorbic acid ＋N-acetyl cysteine groups （P=0.002）. Caerulein-induced pancreatic and liver damage was accompanied with a significant increase in tissue MDA levels （P= 0.01, P= 0.003, respectively） whereas a significant decrease in CAT （P= 0.002, P=0.003, respectively） and GPx activities （P= 0.002, P= 0.03, respectively）. Melatonin and L（＋）-ascorbic acid ＋N-acetyl cysteine administration significantly decreased MDA levels in pancreas （P= 0.03, P= 0.002, respectively） and liver （P= 0.007, P= 0.01, respectively）. Administration of these agents increased pancreatic and hepatic CAT and GPx activities. Melatonin significantly increased pancreatic and hepatic CAT （P= 0.002, P= 0.001, respectively） and GPx activities （P=0.002, P=0.001）. Additionally, L（＋）-ascorbic acid＋N-acetyl cysteine significantly increased pancreatic GPx （P= 0.002） and hepatic CAT and GPx activities （P= 0.001, P= 0.007, respectively） CONCLUSION： Oxidative injury plays an important role not only in the pathogenesis of AP but also in pancreatitis-induced hepatic damage. Antioxidant agents such as melatonin and ascorbic acid＋N-acetyl cysteine, are capable of limiting pancreatic and hepatic damage produced during AP via restoring tissue antioxidant enzyme activities.展开更多
AIM:Microcirculatory disturbances are important early pathophysiological events in various organs during acute pancreatitis.The aim of the study was to evaluate changes in microperfusion of the pancreas,liver,kidney,s...AIM:Microcirculatory disturbances are important early pathophysiological events in various organs during acute pancreatitis.The aim of the study was to evaluate changes in microperfusion of the pancreas,liver,kidney,stomach, colon,skeletal muscle,and to investigate the influence of heparin on the organ microcirculation in caerulein-induced experimental acute pancreatitis. METHODS:Acute pancreatitis was induced by 4 intraperitoneal injections of caerulein(Cn)(15 μg/kg).The organ microcirculation was measured by laser Doppler flowmetry.Serum interleukin 6 and hematocrit levels were analysed. RESULTS:Acute pancreatitis resulted in a significant drop of microperfusion in all examined organs.Heparin administration(2×2.5 mg/kg)improved the microcirculation in pancreas(36.9±4% vs 75.9±10%),liver(56.6±6% vs 75.2±16%),kidney (45.1±6% vs 79.3±5%),stomach (65.2±8% vs 78.1±19%),colon(69.8±6% vs 102.5±19%), and skeletal muscle (59.2±6% vs 77.9±13%).Heparin treatment lowered IL-6(359.0±66 U/mL vs 288.5±58 U/mL) and hematocrit level(53±4% vs 46±3%). CONCLUSION:Heparin administration has a positive influence on organ microcirculatory disturbances accompanying experimental Cn-induced acute pancreatitis.展开更多
AIM: To assess the effect of non-selective ETA/B (LU 302872)and selective ETA (LU 302146) antagonist on pancreatic histology and ultrastructure of acinar cells in connection with trypsinogen activation in early caerul...AIM: To assess the effect of non-selective ETA/B (LU 302872)and selective ETA (LU 302146) antagonist on pancreatic histology and ultrastructure of acinar cells in connection with trypsinogen activation in early caerulein-induced AP.METHODS: Male Wistar rats with caerulein-induced AP,lasting 4 h, were treated i.p. with 10 and 20 mg/kg b.w.of each antagonist. Edema, inflammatory infiltration,necrosis and vacuolization of acinar cells in the pancreas were scored at 0-3 scale. Free active trypsin (FAT), total potential trypsin (TPT) after activation with enterokinase,and index of trypsinogen activation (%FAT/TPT) were assayed in pancreatic homogenates.RESULTS: In untreated AP, the edema, inflammatory infiltration, necrosis and vacuolization increased as compared to control healthy rats (P＜0.01). None of the treatment exerted any meaningful effect on the edema and inflammatory infiltration. The selective antagonist increased slightly the necrosis score to 0.82±0.06 at higher dose (P＜0.05) vs 0.58±0.06 in untreated AP. The nonselective antagonist increased slightly the vacuolization score to 2.41±0.07 at higher dose (P＜0.01) vs 1.88±0.08in untreated AP. The decrease in the number of zymogen granules, disorganization of endoplasmic reticulum,autophagosomes and cytoplasmic vacuoles were more prominent in treated AP than in untreated AP groups.%FAT/TPT in untreated AP increased about four times (18.4±3.8 vs4.8±1.3 in control group without AP, P＜0.001).Treatment of AP with both antagonists did not affect significantly augmented trypsinogen activation.CONCLUSION: The treatment with endothelin-1 receptors (non-selective ETA/B and selective ETA) antagonists has essential effect neither on the edema and inflammatory infiltration nor on trypsinogen activation observed in the early course of caerulein-induced AP. Nevertheless a slight increase of the necrosis and vacuolization score and some of the ultrastructural data could suggest the possibility of their undesired effects in caerulein-induced AP at investigated doses.展开更多
Objective: To establish a refined model of intravenous Caerulein-induced edematous pancreatitis in order to study the pathogenesis and therapeutic protocols of the disesase. Methods: Wistar rats were employed. The osm...Objective: To establish a refined model of intravenous Caerulein-induced edematous pancreatitis in order to study the pathogenesis and therapeutic protocols of the disesase. Methods: Wistar rats were employed. The osmotic pre-filled with Caerulein and saline was implanted into a subctaneous pocket in the left iliac fossa of the animal. Caerulein was then infused via femoral vein to induce pancreatitis. Results: Pathological examination revealed obvious tissue edema of the pancreas in the rat 6 h after Caerulein infusion. The gross appearance of the pancreas exhibited edema with a clear ’gel- like’ fluid separating the pancreatic Iobules. Interstitial edema and marked vacuolization without inflammatory infiltrations in the Caerulein-infused rats were observed with light microscopy. There was no remarkable remarkable changes in the pancer as of rats infused with normal saline. Conclusion: The advantages of using implantable osmotic pump to infuse Caerulein to rats are the facilitation of animal handling, unrestriction of animal movement in cages and reduction in time lost due to accli matization of the rat to new housing conditions.展开更多
AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) a...AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) and pancreatic stress kinase activity was determined. Parameters to assess pancreatitis included trypsin, amylase, lipase, pancreatic weight and histology. RESULTS: JNK inhibition with CEP1347 ameliorated pancreatitis, reducing pancreatic edema. In contrast, p38 inhibition with SB203580 aggravated pancreatitis with higher trypsin levels and, with induction of acinar necrosis not normally found after cerulein hyperstimulation. Simultaneous treatment with both CEP1347 and SB203580 mutually abolished the effects of either compound on cerulein pancreatitis. CONCLUSION: Stress kinases modulate pancreatitis differentially. JNK seems to promote pancreatitis development, possibly by supporting inflammatory reactions such as edema formation while its inhibition ameliorates pancreatitis. In contrast, p38 may help reduce organ destruction while inhibition of p38 during induction of cerulein pancreatitis leads to the occurrence of acinar necrosis.展开更多
文摘AIM： To investigate the role of oxidative injury in pancreatitis-induced hepatic damage and the effect of antioxidant agents such as melatonin, ascorbic acid and N-acetyl cysteine on caerulein-induced pancreatitis and associated liver injury in rats. METHODS： Thirty-eight female Wistar rats were used. Acute pancreatitis （AP） was induced by two i.p. injections of caerulein at 2-h intervals （at a total dose of 100 μg/kg b.wt）. The other two groups received additional melatonin （20 mg/kg b.wt） or an antioxidant mixture containing L（＋）-ascorbic acid （14.3 mg/kb.wt.） and N-acetyl cysteine （181 mg/kg b.wt.） i.p. shortly before each injection of caerulein. The rats were sacrificed by decapitation 12 h after the last injection of caerulein. Pancreatic and hepatic oxidative stress markers were evaluated by changes in the amount of lipid peroxides measured as malondialdehyde （MDA） and changes in tissue antioxidant enzyme levels, catalase （CAT） and glutathione peroxidase （GPx）. Histopathological examination was performed using scoring systems. RESULTS： The degree of hepatic cell degeneration, intracellular vacuolization, vascular congestion, sinusoidal dilatation and inflammatory infiltration showed a significant difference between caerulein and caerulein＋melatonin （P= 0.001）, and careulein and caerulein ＋ L（＋）- ascorbic acid ＋N-acetyl cysteine groups （P= 0.002）. The degree of aciner cell degeneration, pancreatic edema, intracellular vacuolization and inflammatory infiltration showed a significant difference between caerulein and caerulein ＋ melatonin （P=0.004）, and careulein and caerulein ＋ L（＋）-ascorbic acid ＋N-acetyl cysteine groups （P=0.002）. Caerulein-induced pancreatic and liver damage was accompanied with a significant increase in tissue MDA levels （P= 0.01, P= 0.003, respectively） whereas a significant decrease in CAT （P= 0.002, P=0.003, respectively） and GPx activities （P= 0.002, P= 0.03, respectively）. Melatonin and L（＋）-ascorbic acid ＋N-acetyl cysteine administration significantly decreased MDA levels in pancreas （P= 0.03, P= 0.002, respectively） and liver （P= 0.007, P= 0.01, respectively）. Administration of these agents increased pancreatic and hepatic CAT and GPx activities. Melatonin significantly increased pancreatic and hepatic CAT （P= 0.002, P= 0.001, respectively） and GPx activities （P=0.002, P=0.001）. Additionally, L（＋）-ascorbic acid＋N-acetyl cysteine significantly increased pancreatic GPx （P= 0.002） and hepatic CAT and GPx activities （P= 0.001, P= 0.007, respectively） CONCLUSION： Oxidative injury plays an important role not only in the pathogenesis of AP but also in pancreatitis-induced hepatic damage. Antioxidant agents such as melatonin and ascorbic acid＋N-acetyl cysteine, are capable of limiting pancreatic and hepatic damage produced during AP via restoring tissue antioxidant enzyme activities.
基金Supported by Medical University of Gda■sk,grant W-120,Poland
文摘AIM:Microcirculatory disturbances are important early pathophysiological events in various organs during acute pancreatitis.The aim of the study was to evaluate changes in microperfusion of the pancreas,liver,kidney,stomach, colon,skeletal muscle,and to investigate the influence of heparin on the organ microcirculation in caerulein-induced experimental acute pancreatitis. METHODS:Acute pancreatitis was induced by 4 intraperitoneal injections of caerulein(Cn)(15 μg/kg).The organ microcirculation was measured by laser Doppler flowmetry.Serum interleukin 6 and hematocrit levels were analysed. RESULTS:Acute pancreatitis resulted in a significant drop of microperfusion in all examined organs.Heparin administration(2×2.5 mg/kg)improved the microcirculation in pancreas(36.9±4% vs 75.9±10%),liver(56.6±6% vs 75.2±16%),kidney (45.1±6% vs 79.3±5%),stomach (65.2±8% vs 78.1±19%),colon(69.8±6% vs 102.5±19%), and skeletal muscle (59.2±6% vs 77.9±13%).Heparin treatment lowered IL-6(359.0±66 U/mL vs 288.5±58 U/mL) and hematocrit level(53±4% vs 46±3%). CONCLUSION:Heparin administration has a positive influence on organ microcirculatory disturbances accompanying experimental Cn-induced acute pancreatitis.
基金Supported by the Medical University of Bialystok within the Project #30-12770
文摘AIM: To assess the effect of non-selective ETA/B (LU 302872)and selective ETA (LU 302146) antagonist on pancreatic histology and ultrastructure of acinar cells in connection with trypsinogen activation in early caerulein-induced AP.METHODS: Male Wistar rats with caerulein-induced AP,lasting 4 h, were treated i.p. with 10 and 20 mg/kg b.w.of each antagonist. Edema, inflammatory infiltration,necrosis and vacuolization of acinar cells in the pancreas were scored at 0-3 scale. Free active trypsin (FAT), total potential trypsin (TPT) after activation with enterokinase,and index of trypsinogen activation (%FAT/TPT) were assayed in pancreatic homogenates.RESULTS: In untreated AP, the edema, inflammatory infiltration, necrosis and vacuolization increased as compared to control healthy rats (P＜0.01). None of the treatment exerted any meaningful effect on the edema and inflammatory infiltration. The selective antagonist increased slightly the necrosis score to 0.82±0.06 at higher dose (P＜0.05) vs 0.58±0.06 in untreated AP. The nonselective antagonist increased slightly the vacuolization score to 2.41±0.07 at higher dose (P＜0.01) vs 1.88±0.08in untreated AP. The decrease in the number of zymogen granules, disorganization of endoplasmic reticulum,autophagosomes and cytoplasmic vacuoles were more prominent in treated AP than in untreated AP groups.%FAT/TPT in untreated AP increased about four times (18.4±3.8 vs4.8±1.3 in control group without AP, P＜0.001).Treatment of AP with both antagonists did not affect significantly augmented trypsinogen activation.CONCLUSION: The treatment with endothelin-1 receptors (non-selective ETA/B and selective ETA) antagonists has essential effect neither on the edema and inflammatory infiltration nor on trypsinogen activation observed in the early course of caerulein-induced AP. Nevertheless a slight increase of the necrosis and vacuolization score and some of the ultrastructural data could suggest the possibility of their undesired effects in caerulein-induced AP at investigated doses.
文摘Objective: To establish a refined model of intravenous Caerulein-induced edematous pancreatitis in order to study the pathogenesis and therapeutic protocols of the disesase. Methods: Wistar rats were employed. The osmotic pre-filled with Caerulein and saline was implanted into a subctaneous pocket in the left iliac fossa of the animal. Caerulein was then infused via femoral vein to induce pancreatitis. Results: Pathological examination revealed obvious tissue edema of the pancreas in the rat 6 h after Caerulein infusion. The gross appearance of the pancreas exhibited edema with a clear ’gel- like’ fluid separating the pancreatic Iobules. Interstitial edema and marked vacuolization without inflammatory infiltrations in the Caerulein-infused rats were observed with light microscopy. There was no remarkable remarkable changes in the pancer as of rats infused with normal saline. Conclusion: The advantages of using implantable osmotic pump to infuse Caerulein to rats are the facilitation of animal handling, unrestriction of animal movement in cages and reduction in time lost due to accli matization of the rat to new housing conditions.
文摘AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) and pancreatic stress kinase activity was determined. Parameters to assess pancreatitis included trypsin, amylase, lipase, pancreatic weight and histology. RESULTS: JNK inhibition with CEP1347 ameliorated pancreatitis, reducing pancreatic edema. In contrast, p38 inhibition with SB203580 aggravated pancreatitis with higher trypsin levels and, with induction of acinar necrosis not normally found after cerulein hyperstimulation. Simultaneous treatment with both CEP1347 and SB203580 mutually abolished the effects of either compound on cerulein pancreatitis. CONCLUSION: Stress kinases modulate pancreatitis differentially. JNK seems to promote pancreatitis development, possibly by supporting inflammatory reactions such as edema formation while its inhibition ameliorates pancreatitis. In contrast, p38 may help reduce organ destruction while inhibition of p38 during induction of cerulein pancreatitis leads to the occurrence of acinar necrosis.
