Pancreatic microcirculation in acute pancreatitis

We present a review of the microvascular morphology of the pancreas and microstructure of the pancreatic lobule, and report our experimental results of the investigation of pancreatic microcirculation following acute pancreatitis. Impairment of pancreatic microcirculation in the early phase of acute pancreatitis may play a key role in the progression of this disease. Possible contributory mechanisms include increased vascular permeability, reduced blood flow, leukocyte-endothelial cell interaction and intravascular thrombus formation. Using an in-vivo microscope system and off-line computer analysis, we achieved direct visualization and quantification of changes in microvascular permeability and leukocyte behavior in pancreas with acute pancreatitis. Bradykinin and oxygen radicals have been demonstrated to be involved in the increase of vascular permeability in the early stage of caerulein pancreatitis. Leukocyte adherence to the vessels in the pancreatic microcirculation is a secondary event following permeability changes in acute pancreatitis. Leukocyte infiltration during exacerbation of acute pancreatitis is mediated by leukocyte-endothelial cell interaction via leukocyte integrin CD11b/18. Received for publication on Jan. 29, 1997; accepted on April 24, 1997     

急性胰腺炎早期胰腺微循环的改变

目的 探讨急性胰腺炎时胰腺微循环的变化。方法 采用文献回顾的方法．对有关急性胰腺炎时胰腺微循环变化进行综述。结果 在急性胰腺炎早期．胰腺微循环发生了一系列变化。主要表现为微血管收缩，血流速度减慢．血管壁通透性升高，白细胞在毛细血管后小静脉壁上黏附，胰腺灌注量减少等。结论 急性胰腺炎早期胰腺微循环紊乱在胰腺炎的发生、发展中起重要作用。     

Influence of hormonal stimulation by caerulein on acute experimental pancreatitis in the rat

The influence of hormonal stimulation by caerulein administration on acute experimental pancreatitis was investigated in the rat. An experimental model of moderate acute pancreatitis was selected after injecting buffer solution containing sodium taurodeoxycholate and various concentrations of trypsin into the bile-pancreatic duct. During acute experimental pancreatitis caerulein administration increased the mortality rate, the incidence of ascites and the activity of amylase in ascites. Caerulein rendered the pancreatitis more severe also as judged from blind macroscopic evaluation. Amylase and insulin levels in serum and plasma were elevated 6 and 25 h after induction of pancreatitis irrespective of caerulein administration. In pancreatitic rats caerulein decreased the activities of digestive enzymes in pancreatic tissue. The results show that hormonal stimulation by the cholecystokinin-pancreozymin analogue caerulein during acute experimental pancreatitis is harmful.     

Microcirculatory derangement and ischemia of the pancreas]

We present a review of the microvascular morphology of the pancreas and microstructure of the pancreatic lobule, and introduce our experimental results on pancreatic microcirculation following acute pancreatitis. Impairment of pancreatic microcirculation in the early phase of acute pancreatitis may play a key role in the progression of this disease. Possible contributory mechanisms include increased vascular permeability, reduced blood flow, leukocyte-endothelial cell interaction, and intravascular thrombus formation. We achieved direct-visualization and quantification of changes in microvascular permeability and leukocyte behavior in the pancreas with acute pancreatitis using an in vivo microscope system and off-line computer analysis. Bradykinin and oxygen radicals have been demonstrated to be involved in the increased vascular permeability in the early stage of cerulein pancreatitis. Gabexate mesilate (FOY) prevents the increase in vascular permeability, resulting in a decreased number of rolling leukocytes. Leukocyte adherence to the pancreatic microcirculation is a secondary event following permeability changes in acute pancreatitis. Leukocyte infiltration during aggravation of acute pancreatitis is mediated by leukocyte-endothelial cell interaction via leukocyte integrin CD11b/18. The diamino-pyridine derivative IS-741 inhibits the progression of pancreatic inflammation by down-regulating the expression of CD11b/18.     

急性胰腺炎外周循环和胰腺微循环血小板内皮细胞粘附分子-1的表达

目的　探讨急性胰腺炎 (AP)外周循环和胰腺微循环中血小板内皮细胞粘附分子 1(PECAM 1)表达的变化规律。方法　Wistar大鼠 48只 ,诱发AP动物模型 ,用流式细胞仪分析脾静脉和下腔静脉血中多形核白细胞 (PMN )PECAM 1的表达。结果　 ( 1)在急性水肿性胰腺炎(AEP)动物模型中 ,外周循环和胰腺微循环PMNPECAM 1的表达水平在AEP 2、4h组相近 ,自 4h开始 ,外周循环PMNPECAM 1的表达上调直至 8h ;胰腺微循环PMNPECAM 1的表达下调直至 8h ,在AEP 8h组 ,差异有显著性 ( P <0 .0 5 )。 ( 2 )在急性坏死性胰腺炎 (ANP)模型中 ,胰腺微循环PMNPECAM 1的表达下调 ;外周循环组PMNPECAM 1的表达未见明显变化 ,在ANP 4、6h组 ,差异有显著性 (P <0 .0 5 )。结论　AEP胰腺微循环和外周循环PMNPECAM 1的表达呈逆向性 ,在胰腺微循环呈下调趋势 ,在外周循环呈上调趋势 ;ANP胰腺微循环PMNPECAM 1的表达呈加速性下调 ,该结果显示 ,在ANP早期 ,抑制PMNPECAM 1的过度表达可能有助于改善AP病理改变。     

Pancreatic capillary blood flow in an improved model of necrotizing pancreatitis in the rat

INTRODUCTION: The development of acute pancreatitis is characterized by profound changes in pancreatic microcirculation. Using in vivo microscopy with fluorescent-labeled erythrocytes as tracers we studied changes in pancreatic microcirculation in an improved rat model of necrotizing pancreatitis (NP) in comparison to edematous pancreatitis (EP) and healthy controls. METHODS: Twenty-one male Wistar rats had their pancreatae exteriorized in a temperature-controlled immersion chamber followed by intravenous administration of fluorescent-labeled autologous erythrocytes. EP was induced by intraductal saline and intravenous caerulein (5 microg/kg/h) for 6 h (n = 7) and NP by controlled intraductal infusion of glycodeoxycholic acid (10 mmol/L) followed by intravenous caerulein (n = 7). Control animals received intraductal and intravenous saline (n = 7). The determination of pancreatic microcirculation was performed before as well as 1, 3, and 6 h after intraductal infusion by correlating the number of passing labeled erythrocytes/capillary/min with their concentration per microliter of arterial blood. RESULTS: Pancreatic capillary flow in control animals remained constant over the 6-h observation period. Pancreatic capillary flow in the EP group rapidly increased to 188% of baseline after 3 h and remained significantly elevated throughout the experiments (P = 0.0001). In contrast, pancreatic capillary flow decreased significantly in the group suffering NP with values 46.7% of baseline after 6 h (P = 0.0001). Complete capillary stasis developed in 38% of investigated capillaries in the NP group compared to 0-1% in both other groups (P = 0.0001). CONCLUSION: Pancreatic microcirculation in mild edematous pancreatitis is significantly increased while the evolution of necrotizing pancreatitis in the model studied herein is characterized by a dramatic reduction in pancreatic capillary flow in conjunction with areas of capillary stasis. These results underline the pathophysiologic relevance of the model and of therapeutic measures aimed at an improvement of pancreatic microcirculation in clinical necrotizing pancreatitis.     

The relative safety of MRI contrast agent in acute necrotizing pancreatitis.

OBJECTIVE: To validate the safety of gadolinium-diethylenetriamine pentaacetic acid (GD-DTPA) by measuring its effect on pancreatic capillary perfusion and acinar injury in acute pancreatitis. BACKGROUND: Contrast-enhanced computed tomography (CECT) is proposed as a gold standard for early evaluation of acute necrotizing pancreatitis. However, iodinated contrast media used for CECT have been shown in these circumstances to reduce pancreatic capillary flow and increase necrosis and mortality. Recent reports suggest that post-GD MRI provides images comparable to CECT in the assessment of severe acute pancreatitis. METHODS: Necrotizing pancreatitis was induced in 14 Wistar rats by intraductal glycodeoxycholic acid (10 mM/L) and intravenous caerulein (5 microg/kg/h) over 6 hours. Intravital microscopic quantitation of pancreatic capillary blood flow was performed using fluorescein isothiocyanate-labeled erythrocytes after induction of pancreatitis and 30 and 60 minutes after an intravenous bolus of either Ringer's solution or GD-DTPA (0.2 mL/kg). RESULTS: The two study groups were comparable with regard to mean arterial pressure, heart rate, arterial blood gases, hematocrit, amylase, lipase, and trypsinogen activation peptide production throughout the experiment. GD-DTPA did not reduce capillary flow (1.93 +/- 0.05 nL/capillary/min) compared to animals infused with Ringer's solution (1.90 +/- 0.06 nL/capillary/min). CONCLUSIONS: Intravenous injection of GD-DTPA does not further impair pancreatic microcirculation or increase acinar injury in acute necrotizing pancreatitis. Because of this advantage over CT contrast medium, further development of MRI as a staging tool in acute pancreatitis seems desirable.     

遏制轻型急性胰腺炎向重症转化的非手术 治疗策略

目的 ：探讨遏制急性胰腺炎向重症转化的非手术治疗策略。方法 ：将4年间收治的286例轻型急性胰腺炎分为对照组和治疗观察组。对照组采取常规非手术治疗措施;观察组加用改善胰腺微循环，防治细胞钙超载和抑制胰酶的治疗方法。结果 ：对照组144轻型有20例转化为重症胰腺炎，14例发生全身性并发症;观察组142例轻型有8例转化为重症，2例出现全身性并发症。观察组重症患者血C-反应蛋白和Balthazar CT严重度指数在治疗后各时点较对照组明显降低。结论 ：在常规治疗的基础上加用改善胰腺微循环，防治细胞钙超载和抑制胰酶的治疗措施可能有助于阻止轻型急性胰腺炎向重症化发展。     

Therapeutic effect of isovolemic hemodilution with dextran 60 on the impairment of pancreatic microcirculation in acute biliary pancreatitis.

Dextran of different molecular weight (Dx 40, Dx 60/70) has often been evaluated as adjunct treatment of experimental acute pancreatitis. A beneficial effect has been documented by a decrease in its lethality. However, the mechanism of action is poorly understood. A specific effect on the pancreatic microcirculation generally has not been documented and differentiation from unspecific improvement of pancreatic blood flow due to volume expansion has been difficult. This investigation was designed to quantify the effect of dextran on the impairment of pancreatic microcirculation during acute biliary pancreatitis by means of intravital microscopy. Dextran 60 (Dx 60, molecular weight 60,000) was chosen in light of the increase in vascular permeability in the early stage of pancreatitis as demonstrated previously in the same model. Isovolemic hemodilution, i.e., exchange of whole blood for Dx 60 was used as a mode of administration to achieve instantaneous onset of therapy without changes in intravascular volume. In the control group a progressive reduction of pancreatic capillary perfusion commenced 30 minutes after induction of acute pancreatitis, resulting in cessation of nutritive tissue perfusion after 3 hours. In the animals subjected to hemodilution, stabilization of the pancreatic microcirculation was accomplished throughout the observation period of 6 hours. Because volume-related effects could be excluded by the protocol and by monitoring central venous pressure and hematocrit, a specific effect of hemodilution with DX 60 on the pancreatic microcirculation is indicated by our results.     

Thromboxane A2 receptor antagonist prevents pancreatic microvascular leakage in rats with caerulein-induced acute pancreatitis

This study was designed to evaluate the protective effect of thromboxane A2 (TXA2) receptor antagonist, seratrodast, against pancreatic injuries during acute pancreatitis. Acute pancreatitis was induced in rats by intravenous infusion of a supramaximal dose of caerulein (5 microg/kg x h for 4 h). In this model, marked hyperamylasemia, a significant increase in pancreatic water content, and a significant increase in pancreatic micro-vascular leakage of Evans blue dye were observed. Pancreatic subcellular redistribution of a lysosomal enzyme, cathepsin B from the lysosomal fraction to the zymogen fraction as well as a significant increase in pancreatic trypsin content were also observed. Pretreatment with seratrodast at a dose of 2 mg/kg (twice, 8 and 4 h before caerulein infusion) significantly inhibited these pancreatic injuries including hyperamylasemia, increased pancreatic microvascular leakage, redistribution of cathepsin B and increased pancreatic trypsin content. These results suggest that TXA2 may be involved in the pathogenesis of acute pancreatitis in the early stage of the disease and that TXA2 receptor antagonist might be of therapeutic value for treatment of acute pancreatitis.     

Pulmonary microcirculation in mild and severe experimental pancreatitis

BACKGROUND: Research aimed at elucidating the pathogenesis of pancreatitis-associated lung injury and evaluating novel strategies for preventing respiratory complications in acute pancreatitis (AP) has not yet involved intravital microscopic (IVM) studies of pulmonary microcirculation in animals with severe disease. OBJECTIVE: To characterize and compare pulmonary microcirculation in severe/necrotizing (NP) and mild/edematous pancreatitis (EP) in the rat. METHODS: EP was induced by intravenous cerulein infusion (n = 10) and NP by a standardized intraductal infusion of glycodeoxycholic acid followed by intravenous cerulein (n = 10). After 24 h a left-sided thoracotomy was performed for IVM examination of pulmonary capillary blood flow, permeability, leukocyte sticking and the thickness of alveolar septi. Further measurements included monitoring of arterial blood gases and histological evaluation of lung injury. RESULTS: In animals with NP, histology revealed severe pulmonary edema together with clustering of polymorphonuclear leukocytes in pulmonary microvessels and alveoli. IVM showed a greater number (n) of leukocytes sticking on the endothelium of pulmonary capillaries (9.4 +/- 0.7 vs. 1.8 +/- 0.2 in healthy control animals) and increased capillary permeability (260 +/- 14 vs. 136 +/- 6% relative fluorescein intensity) while capillary blood flow was decreased (0.41 +/- 0.05 vs. 0.57 +/- 0.03 mm/s). In comparison, changes in EP were significantly less pronounced (flow 0.5 +/- 0.04 mm/s, permeability 156 +/- 4%, leukocyte sticking n = 4.6 +/- 0.7). CONCLUSIONS: These findings suggest that deterioration of pulmonary microcirculation in AP correlates with disease severity and that a model featuring NP may therefore be more suitable to further study pancreatitis-associated pulmonary injury.     

Renal microcirculation in experimental acute pancreatitis of dogs--the effect of pancreatic protease inhibitor and dopamine

To understand the renal microcirculation in acute pancreatitis is important to know the pathophysiology of renal insufficiency frequently observed as one of multiple organ failures in severe acute pancreatitis. In mongrel dogs acute pancreatitis was experimentally introduced by autologous bile added trypsin injection into the pancreatic duct. The effect of new synthesized pancreatic protease inhibitor (PATM) and dopamine in a dose of 3mg/kg/hr and 10 micrograms/kg/min were investigated, respectively. In acute pancreatitis dogs, renal arterial blood flow and renal tissue blood flow immediately fell and gradually decreased in time course of experiment and renal vascular resistance increased from 2 hours after onset of pancreatitis. When pancreatic protease inhibitor (PATM) was infused in acute pancreatitis dogs, blood pressure and pulse pressure relatively preserved during the experiment. Renal blood flow and renal tissue blood flow were maintained during the first 1 hour and thereafter slightly decreased, however which was less than that of no PATM treated dogs. When dopamine was infused in acute pancreatitis dogs, blood pressure was maintained during the first 90 minutes thereafter remarkably decreased. Renal blood flow was maintained within 60 minutes, however it remarkably decreased at the end of the experiment. This study suggested that renal microcirculation was disturbed from early period of acute pancreatitis in dogs and pancreatic protease inhibitor (PATM) had a beneficial effect of maintain the renal microcirculation.     

Treatment with Met-RANTES reduces lung injury in caerulein-induced pancreatitis

BACKGROUND: Severe acute pancreatitis leads to a systemic inflammatory response characterized by widespread leucocyte activation and, as a consequence, distant lung injury. In CC chemokines the first two cysteine residues are adjacent to each other. The aim of this study was to evaluate the effect of Met-RANTES, a CC chemokine receptor antagonist, on pancreatic inflammation and lung injury in caerulein-induced acute pancreatitis in mice. METHODS: Acute pancreatitis was induced in mice by hourly intraperitoneal injection of caerulein. Met-RANTES was administered either 30 min before or 1 h after starting caerulein injections, and pancreatic inflammation and lung injury were assessed. There were five groups of eight mice each including controls. RESULTS: Treatment with Met-RANTES had little effect on caerulein-induced pancreatic damage. Met-RANTES, however, reduced lung injury when given either before administration of caerulein (mean(s.e.m.) lung myeloperoxidase (MPO) 1.47(0.19) versus 3.70(0.86)-fold increase over control, P = 0.024; mean(s.e.m.) microvascular permeability 1.15(0.05) versus 3.57(0.63) lavage to plasma fluorescein isothiocyanate-labelled albumin fluorescence ratio (L/P) per cent, P = 0.002) or after caerulein administration (lung MPO 1.96(0.27) versus 3.65(0.63)-fold increase over control, P = 0.029; microvascular permeability 0.94(0.04) versus 2.85(0.34) L/P per cent, P < 0.001). CONCLUSION: Treatment with Met-RANTES reduces lung damage associated with caerulein-induced pancreatitis in mice. Chemokine receptor antagonists may be of use for the treatment of the systemic complications of acute pancreatitis.     

Technetium-99m-labeled white blood cells: a new method to define the local and systemic role of leukocytes in acute experimental pancreatitis.

OBJECTIVE: We developed a new method to quantitate leukocyte accumulation in tissues and used it to examine the time course and severity of acute experimental pancreatitis. BACKGROUND: Leukocyte activation and infiltration are believed to be critical steps in the progression from mild to severe pancreatitis and responsible for many of its systemic complications. METHODS: Pancreatitis of graded severity was induced in Sprague-Dawley rats with a combination of caerulein and controlled intraductal infusion. Technetium-99m (99mTc)-labeled leukocytes were quantified in pancreas, lung, liver, spleen, and kidney and compared with myeloperoxidase activity. The severity of pancreatitis was ascertained by wet/dry weight ratio, plasma amylase, and trypsinogen activation peptide in the pancreas. The time course of leukocyte accumulation was determined over 24 hours. RESULTS: Pancreatic leukocyte infiltration correlated well with tissue myeloperoxidase concentrations. In mild pancreatitis, leukocytes accumulated only in the pancreas. Moderate and severe pancreatitis were characterized by much greater leukocyte infiltration in the pancreas than in mild disease (p < 0.01), and increased 99mTc radioactivity was detectable in the lung as early as 3 hours. 99mTc radioactivity correlated directly with the three levels of pancreatitis. CONCLUSIONS: Mild pancreatitis is characterized by low-level leukocyte activation and accumulation in the pancreas without recruitment of other organs; marked leukocyte accumulation was found in the pancreas and in the lung in more severe grades of pancreatitis. These findings provide a basis for the pathophysiologic production of cytokines and oxygen free radicals, which potentiate organ injury in severe pancreatitis. This study validates a new tool to study local and systemic effects of leukocytes in pancreatitis as well as new therapeutic hypotheses.     

中药复方TCMP-1对急性胰腺炎血小板内皮细胞粘附分子-1表达变化的研究

目的 探讨急性水肿性胰腺炎(AEP)血小板内皮细胞粘附分子-1(PECAM-1)表达的变化规律及中药复方TCMP-1对AEP的治疗作用。方法 Wistar大鼠54只,诱发AEP动物模型,并给予TCMP-1干预,用流式细胞仪分析脾静脉血中多形核白细胞(PMN)PECAM-1的表达。结果 (1)在AEP自然病程组中,外周循环和胰腺微循环PMN PECAM-1的表达水平在AEP 2、4 h组相近,自AEP 4 h组开始,外周循环PECAM-1的表达上调直至AEP 8 h组;胰腺微循环PECAM-1的表达下调直至AEP 8 h组;在AEP 8 h组,PMN PECAM-1的表达有显著性差异(P<0.05)。(2)在AEP 8 h治疗组与AEP 8 h自然病程组中,体循环PMN PECAM-1的表达有显著性差异(P<0.05)。结论 (1)下调体循环PMN PECAM-1的表达水平或抑制PMN PECAM-1的过度表达,可以阻止胰腺微循环中PMN与内皮细胞的粘附。(2)抑制PMN PECAM-1的过度表达是中药复方TCMP-1实现其疗效作用的主要机制之一。     

Therapy for microcirculatory disorders in severe acute pancreatitis: Effectiveness of platelet-activating factor receptor blockade vs. endothelin receptor blockade

Many of the complications of severe acute pancreatitis are the result of the amplifying effects of microcirculatory disruption. The factors causing microcirculatory disorders in acute pancreatitis involve vasoactive mediators such as platelet-activating factor (PAF) and endothelin-1 (ET) activated during the inflammatory response to pancreatic injury. To further evaluate the potential therapeutic role of specific receptor antagonists (RA) to these mediators, the present study compares the effect of PAF and ET receptor blockade on microcirculation and organ function in a well-established rodent model of severe acute pancreatitis. Six hours after acute pancreatitis induction, rats were randomized to therapy with ET-RA (50 mg/kg LU-135252), PAF-RA (82 μg/kg WEB-2170), or NaCl 0.9% (volume equivalent). After 18 hours of fluid resuscitation, animals were relaparototnized for intravital microscopic determination of capillary blood flow, leukocyte rolling, and capillary permeability in the pancreas and colon. Other measurements included cardiorespiratory parameters, hematocrit, pleural effusions, ascites, urine production, and survival. Compared to saline treatment both ET-RA and PAF-RA significantly improved capillary blood flow in the pancreas and colon, reduced leukocyte rolling, and stabilized capillary permeability. The beneficial effects of receptor antagonist treatment on microcirculation were associated with decreased fluid loss into the third space, improved renal and respiratory function, and survival. Although both receptor antagonists likewise improved capillary blood flow, ET-RA was significantly more effective in counteracting leukocyte rolling and capillary leakage, thereby further reducing fluid sequestration. The present study confirms the beneficial effects of PAF and ET receptor blockade on microcirculation inside and outside the pancreas, organ function, and survival when given at the early stage of severe pancreatitis. Because ET-RA was more effective in stabilizing capillary permeability and avoiding subsequent fluid loss into the third space, we propose that ET-RA should be tested in a clinical trial (either in comparison or in addition to PAF-RA). Presented at the Thirty-Ninth Annual Meeting of The Society for Surgery of the Alimentary Tract, New Orleans, La., May 17–20, 1998.     

Platelet Function in Acute Experimental Pancreatitis

Acute pancreatitis (AP) is characterized by disturbances of pancreatic microcirculation. It remains unclear whether platelets contribute to these perfusion disturbances. The aim of our study was to investigate platelet activation and function in experimental AP. Acute pancreatitis was induced in rats: (1) control (n = 18; Ringer’s solution), (2) mild AP (n = 18; cerulein), and (3) severe AP (n = 18; glycodeoxycholic acid (GDOC) + cerulein). After 12 h, intravital microscopy was performed. Rhodamine-stained platelets were used to investigate velocity and endothelial adhesion in capillaries and venules. In addition, erythrocyte velocity and leukocyte adhesion were evaluated. Serum amylase, thromboxane A2, and histology were evaluated after 24 h in additional animals of each group. Results showed that 24 h after cerulein application, histology exhibited a mild AP, whereas GDOC induced severe necrotizing AP. Intravital microscopy showed significantly more platelet–endothelium interaction, reduced erythrocyte velocity, and increased leukocyte adherence in animals with AP compared to control animals. Thromboxane levels were significantly elevated in all AP animals and correlated with the extent of platelet activation and severity of AP. In conclusion, platelet activation plays an important role in acute, especially necrotizing, pancreatitis. Mainly temporary platelet–endothelium interaction is observed during mild AP, whereas severe AP is characterized by firm adhesion with consecutive coagulatory activation and perfusion failure. Parts of the results of this study were presented at the congress of the German Surgical Society, Berlin (May 2004), the Digestive Disease Week (May 2004), and the Annual Meeting of the American Pancreatic Association, Chicago (November 2004).     

Changes of lysosomal and digestive enzymes in rat caerulein pancreatitis]

We evaluated the changes of lysosomal and digestive enzymes in the exocrine pancreas after caerulein induced acute pancreatitis in rats. The serum amylase levels and water content as well as pancreatic amylase and cathepsin B contents increased significantly in the early stage (0-12 h) after caerulein was administered, however, returned to the normal levels at 36 h. In the early stage, colocalization of lysosomal enzyme and digestive enzyme was found. Histologically, in the early stage, there were remarkable changes such as acinar cell vacuolization and interstitial edema, but these changes disappeared at 36 h. Furthermore, amylase and cathepsin B outputs decreased significantly in the early stage (12 h) but at 24 h, these increased significantly. LDH discharge from dispersed acini and cathepsin B leakage from lysosomes also increased in the early stage (0-12 h), but these values returned to the normal levels at 36 h. These results indicate that exocrine pancreas needs about 36 h to recover from the caerulein induced acute pancreatitis, and in this recovering process, secretion of colocalized digestive enzyme and lysosomal enzyme seem to play an important role.     

Diaspirin cross-linked hemoglobin effectively restores pancreatic microcirculatory failure in hemorrhagic shock

BACKGROUND: Microvascular reperfusion failure of splanchnic organs is a crucial hallmark in organ damage induced by hemorrhagic shock, which should be prevented by a resuscitation solution. Because the vasoactive properties of the hemoglobin-based oxygen carrier diaspirin cross-linked hemoglobin (DCLHb) could adversely influence restoration of pancreatic capillary perfusion during resuscitation, the authors investigated its effects on the microcirculation of the rat pancreas in comparison with whole blood and 6% hydroxyethylstarch resuscitation from severe hemorrhagic shock. METHODS: Twenty-eight pentobarbital-anaesthetized rats were bled to a mean arterial pressure (MAP) of 40 mmHg and maintained at this level for 1 h. Using an intravital microscope, mean arterial pressure, the length of erythrocyte-perfused pancreatic capillaries per observation area (functional capillary density), the adherence of leukocytes in postcapillary venules, and pancreatic lipid peroxidation, measured as thiobarbituric acid-reactive material in pancreatic tissue, were determined in animals resuscitated by volumes of hydroxyethylstarch, DCLHb, and whole blood (WB) equivalent to the shed blood volume or in control animals without shock induction for a period of 2 h after resuscitation. RESULTS: Compared with control animals (366+/-28 cm(-1)), animals resuscitated with DCLHb (294+/-45 cm(-1)), WB (306+/-11 cm(-1)), and hydroxyethylstarch (241+/-34 cm(-1)) showed a significant reduction of functional capillary density after 2 h of resuscitation. DCLHb was as effective as WB and superior to hydroxyethylstarch in restoring functional capillary density and mean arterial pressure. Leukocyte adherence in postcapillary venules was not enhanced by DCLHb (369+/-148/mm2) infusion when compared with hydroxyethylstarch- (615+/-283/mm2) and WB-treated (510+/-415/mm2) animals. Lipid peroxidation of pancreatic tissue was significantly elevated after treatment with both oxygen-carrying solutions compared with hydroxyethylstarch. CONCLUSION: DCLHb is as effective as WB for preservation of the pancreatic microcirculation.