Dynamic intravital fluorescence microscopy--a novel method for the assessment of microvascular permeability in acute pancreatitis

Intravital Imaging of Leukocyte-Endothelial Interaction in Hindlimb Ischemia/Reperfusion Injury by Intravital Multiphoton Microscopy

Ischemia/reperfusion injury in skeletal muscle leads to sterile inflammation and affects structure and function permanently. However, the main understanding of the molecular and cellular mechanisms mainly relies on in vitro and ex vivo investigations. Recent advances in intravital microscopy allow for insights into dynamic processes at the cellular and subcellular level under both physiological and pathophysiological conditions. Real-time intravital imaging by two-photon microscopy (2P-IVM) has emerged as a powerful tool in the evaluation of the cell-cell interaction and molecular biology of leukocytes in live animals. Acute ischemic injury in limbs may occur due to crush syndrome, compartment syndrome, and vascular diseases and injury as in acute peripheral arterial occlusion, caused by a diverse array of pathological conditions. Iatrogenic revascularization and restoration of perfusion results paradoxically in aggravated tissue injury. Furthermore, the effects of IR-injured skeletal muscle in clinical conditions such as compartment syndrome or crush syndrome may induce rhabdomyolysis and are associated with so-called remote injuries as acute kidney dysfunction. Here, we discuss the considerations for and describe a 2P-IVM method designed for visualization of leukocyte-endothelial interaction. This chapter will provide a detailed experimental setup and a step-by-step protocol for the dynamic imaging of leukocyte-endothelial-interaction in an ischemia/reperfusion injury model.

Stabilization and improved functionality of three-dimensional perfusable microvascular networks in microfluidic devices under macromolecular crowding

BACKGROUND

There is great interest to engineer in vitro models that allow the study of complex biological processes of the microvasculature with high spatiotemporal resolution. Microfluidic systems are currently used to engineer microvasculature in vitro, which consists of perfusable microvascular networks (MVNs). These are formed through spontaneous vasculogenesis and exhibit the closest resemblance to physiological microvasculature. Unfortunately, under standard culture conditions and in the absence of co-culture with auxiliary cells as well as protease inhibitors, pure MVNs suffer from a short-lived stability.

METHODS

Herein, we introduce a strategy for stabilization of MVNs through macromolecular crowding (MMC) based on a previously established mixture of Ficoll macromolecules. The biophysical principle of MMC is based on macromolecules occupying space, thus increasing the effective concentration of other components and thereby accelerating various biological processes, such as extracellular matrix deposition. We thus hypothesized that MMC will promote the accumulation of vascular ECM (basement membrane) components and lead to a stabilization of MVN with improved functionality.

RESULTS

MMC promoted the enrichment of cellular junctions and basement membrane components, while reducing cellular contractility. The resulting advantageous balance of adhesive forces over cellular tension resulted in a significant stabilization of MVNs over time, as well as improved vascular barrier function, closely resembling that of in vivo microvasculature.

CONCLUSION

Application of MMC to MVNs in microfluidic devices provides a reliable, flexible and versatile approach to stabilize engineered microvessels under simulated physiological conditions.

Intravital Microscopy Imaging Approaches for Image-Guided Drug Delivery Systems

Rapid technical advances in the field of non-linear microscopy have made intravital microscopy a vital pre-clinical tool for research and development of imaging-guided drug delivery systems. The ability to dynamically monitor the fate of macromolecules in live animals provides invaluable information regarding properties of drug carriers (size, charge, and surface coating), physiological, and pathological processes that exist between point-of-injection and the projected of site of delivery, all of which influence delivery and effectiveness of drug delivery systems. In this Review, we highlight how integrating intravital microscopy imaging with experimental designs (in vitro analyses and mathematical modeling) can provide unique information critical in the design of novel disease-relevant drug delivery platforms with improved diagnostic and therapeutic indexes. The Review will provide the reader an overview of the various applications for which intravital microscopy has been used to monitor the delivery of diagnostic and therapeutic agents and discuss some of their potential clinical applications.

Everolimus Improves Microcirculatory Derangements in Experimental Postischemic Pancreatitis Modulating the Expression of Vascular Endothelial Growth Factor, Interleukin 6, and Toll-Like Receptor 4

OBJECTIVES

Ischemia/reperfusion injury (IRI) of the pancreas is a serious complication following pancreatic transplantation and hemorrhagic shock. The present study was designed to investigate the influence of the potent mammalian target of rapamycin inhibitor everolimus interfering via microvascular permeability changing key proteins hypoxia-inducible factor (HIF) and vascular endothelial growth factor on pancreatic IRI-induced microvascular disturbances.

METHODS

Anesthetized male Sprague-Dawley rats were assigned to 3 groups (n = 7/group): (1) sham, (2) 60-minute ischemia/reperfusion of the pancreas (I/R), and (3) I/R and everolimus (10 mg/kg BW orally). Quantification of the effective microvascular permeability (P), functional capillary density (FCD), and leukocyte-endothelial cell interaction (LEI) was performed using digital and analog intravital epifluorescence microscopy. Serum-amylase, lipase, interleukin 6, and vascular endothelial growth factor concentration were quantified using enzyme-linked immunosorbent assay.

RESULTS

Sham compared with I/R (P: [×10 cm/s] 0.068 ± 0.079 vs 1.516 ± 0.314; FCD: [cm/cm] 357 ± 14 vs 258 ± 13; LEI: [cells/mm] 148 ± 25 vs 349 ± 75) demonstrates a significant increase in microcirculatory damage and all previously mentioned serum parameters. Except amylase, I/R + everolimus led to a statistically significant improvement of almost all increased parameters (P: 0.434 ± 0.296, FCD: 347 ± 16, LEI: 178 ± 30).

CONCLUSIONS

Everolimus attenuated experimental microvascular and inflammatory IRI of the pancreas. Therefore, these results may warrant further investigation of everolimus as a therapeutic agent following clinical states with pancreatic ischemia/reperfusion.

Effects of dexamethasone and Salvia miltiorrhiza on multiple organs in rats with severe acute pancreatitis

OBJECTIVE

To investigate the protective effects and mechanisms of action of dexamethasone and Salvia miltiorrhiza on multiple organs in rats with severe acute pancreatitis (SAP).

METHODS

The rats were divided into sham-operated, model control, dexamethasone treated, and Salvia miltiorrhiza treated groups. At 3, 6, and 12 h after operation, the mortality rate of different groups, pathological changes, Bcl-2-associated X protein (Bax) and nuclear factor-κB (NF-κB) protein expression levels in multiple organs (the pancreas, liver, kidneys, and lungs), toll-like receptor 4 (TLR-4) protein levels (only in the liver), intercellular adhesion molecule 1 (ICAM-1) protein levels (only in the lung), and terminal deoxynucleotidy transferase mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) staining expression levels, as well as the serum contents of amylase, glutamate-pyruvate transaminase (GPT), glutamic-oxaloacetic transaminase (GOT), blood urea nitrogen (BUN), and creatinine (CREA) were observed.

RESULTS

The mortality rate of the dexamethasone treated group was significantly lower than that of the model control group (P<0.05). The pathological changes in multiple organs in the two treated groups were relieved to different degrees (P<0.05 and P<0.01, respectively), the expression levels of Bax and NF-κB proteins, and apoptotic indexes of multiple organs were reduced (P<0.05 and P<0.01, respectively). The contents of amylase, GPT, GOT, BUN, and CREA in the two treated groups were significantly lower than those in model control groups (P<0.05 and P<0.01, respectively). The expression level of ICAM-1 protein in the lungs (at 3 and 12 h) in the dexamethasone treated group was significantly lower than that in the Salvia miltiorrhiza treated group (P<0.05). The serum contents of CREA (at 12 h) and BUN (at 6 h) of the Salvia miltiorrhiza treated group were significantly lower than those in the dexamethasone treated group (P<0.05).

CONCLUSIONS

Both dexamethasone and Salvia miltiorrhiza can reduce the inflammatory reaction, regulate apoptosis, and thus protect multiple organs of rats with SAP.

Protective effects of Ligustrazine, Kakonein and Panax Notoginsenoside on the small intestine and immune organs of rats with severe acute pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) is characterized by fatal pathogenic conditions and a high mortality. It is important to study SAP complicated with multiple organ injury. In this study we compared the protective effects of three traditional Chinese medicines (Ligustrazine, Kakonein and Panax Notoginsenoside) on the small intestine and immune organs (thymus, spleen and lymph nodes) of rats with SAP and explored their mechanism of action.

METHODS

One hundred forty-four rats with SAP were randomly divided into model control, Ligustrazine-treated, Kakonein-treated, and Panax Notoginsenoside-treated groups (n=36 per group). Another 36 normal rats comprised the sham-operated group. According to the different time points after operation, the experimental rats in each group were subdivided into 3-, 6- and 12-hour subgroups (n=12). At various time points after operation, the mortality rate of rats and pathological changes in the small intestine and immune organs were recorded and the serum amylase levels were measured.

RESULTS

Compared to the model control groups, the mortality rates in all treated groups declined and the pathological changes in the small intestine and immune tissues were relieved to different degrees. The serum amylase levels in the three treated groups were significantly lower than those in the model control group at 12 hours. The pathological severity scores for the small intestinal mucosa, thymus and spleen (at 3 and 12 hours) in the Ligustrazine-treated group, for the thymus (at 3 and 12 hours) and spleen (at 3 and 6 hours) in the Kakonein-treated group, and for the thymus (at 3 hours) and spleen (at 3 hours) in the Panax Notoginsenoside-treated group were significantly lower than those in the model control group. The pathological severity scores of the small intestinal mucosa (at 6 and 12 hours) and thymus (at 6 hours) in the Ligustrazine-treated group were significantly lower than those in the Kakonein- and Panax Notoginsenoside-treated groups.

CONCLUSIONS

All the three traditional Chinese drugs significantly alleviated the pathological changes in the small intestine and immune organs of SAP rats. Ligustrazine was the most effective one among them.

64-slice CT perfusion imaging of pancreatic adenocarcinoma and mass-forming chronic pancreatitis

RATIONALE AND OBJECTIVES

To investigate 64 computed tomography (CT) perfusion imaging features of patients with pancreatic cancer and mass-forming chronic pancreatitis.

MATERIALS AND METHODS

Between January 2003 and April 2010, 234 patients with pancreatic mass underwent 64-CT perfusion imaging. Among them, the histopathological results of 64 patients were proven to be pancreatic adenocarcinoma and 15 patients were proven to be mass-forming chronic pancreatitis. Additionally, CT perfusion imaging was performed in 33 healthy volunteers served as controls. The slice data were processed using CT perfusion software. Perfusion parameters including time density curve, blood flow, blood volume, permeability, peak enhancement, and time to peak were recorded.

RESULTS

Blood flow was 77% lower in patients with pancreatic adenocarcinoma than in controls, 48% lower in patients with mass-forming chronic pancreatitis than in controls, and 56% lower in patients with pancreatic adenocarcinoma than with mass-forming chronic pancreatitis (P < .016). Blood volume was 65% lower in pancreatic adenocarcinoma than in controls, 27% lower in mass-forming chronic pancreatitis than in controls, and 53% lower in cancer than mass-forming chronic pancreatitis (P < .016). Permeability was 559% higher in pancreatic adenocarcinoma than in controls, 821% higher in mass-forming chronic pancreatitis than in controls, and 28% lower in cancer than mass-forming chronic pancreatitis (P < .016). Peak enhancement was 27% lower and time to peak 23% longer in pancreatic adenocarcinoma than mass-forming chronic pancreatitis (P < .016). Time-density curve showed the peak of mass-forming chronic pancreatitis is earlier and higher than that of pancreatic adenocarcinoma, and the peak of mass-forming chronic pancreatitis is later and lower than that of controls.

CONCLUSION

CT perfusion imaging can provide additional quantitative hemodynamic information of pancreatic adenocarcinoma and mass-forming chronic pancreatitis.

Preconditioning of pancreatic graft with isoproterenol reduces posttransplant ischemia/reperfusion injury in rats

AIM: To determine the protective effects of isoproterenol preconditioning (IPC) against ischemia/reperfusion injury in rats after pancreas transplantation and to explore mechanisms involved.

METHODS: The expression of heat shock protein 70 (HSP70) in the pancreas of rats undergoing IPC was detected at different time points after IPC. A rat model of posttransplant pancreatic ischemia/reperfusion injury was established. The donor rats that showed high expression of HSP70 in the pancreas were used as experiment group, while donor rats that did not undergo IPC were used as control group. The blood and pancreatic samples were taken 6 h after pancreas transplantation. The expression of HSP70 in the pancreas was detected by Western blot and immunohistochemistry. The expression of TNF-α in the pancreas was detected by immunohistochemistry. Serum amylase was determined by iodine colorimetry. The apoptosis rate of pancreatic cells was determined by flow cytometry.

RESULTS: The expression level of HSP70 in the pancreas of donor rats reached the peak at 24 h after IPC, which was significantly higher than those at other time points (0.92 ± 0.25 vs 0.24 ± 0.04, 0.34 ± 0.06, 0.58 ± 0.07, 0.62 ± 0.11 and 0.25 ± 0.09, respectively; all P < 0.05). The expression levels of HSP70 in the experimental group at 6, 12, 24 and 36 h after IPC were significantly higher than those in the control group at corresponding time points (0.34 ± 0.06 vs 0.28 ± 0.07, 0.58 ± 0.07vs 0.25 ± 0.04, 0.92 ± 0.25 vs 0.27 ± 0.05 and 0.62 ± 0.11 vs 0.25 ± 0.06, respectively; all P < 0.05) but returned to normal level at 48 h. No significant differences were noted in the expression levels of HSP70 among each time point in the control group. HSP70 was mainly expressed in pancreatic acinar cells and the vessel wall. The expression level of TNF-α, apoptosis rate, neutrophil count and serum amylase significantly increased in the control group when compared with those in sham-operated group (all P < 0.01). However, the levels of these parameters significantly decreased in the experiment group when compared with those in the control group (11 929 ± 1 220 vs 46 111 ± 3 127, 26.7% ± 4.5% vs 37.4% ± 4.7%, 3 308 ± 531 vs6 668 ± 1 506 and 1 057 IU/L± 148 IU/L vs 1 408 IU/L± 195 IU/L, respectively; all P < 0.05).

CONCLUSION: Isoproterenol preconditioning reduces ischemia/reperfusion injury in rats after pancreas transplantation perhaps by inducing the production of HSP70.

Effect of baicalin on inflammatory mediator levels and microcirculation disturbance in rats with severe acute pancreatitis

OBJECTIVES

To investigate the effect of bacailin on inflammatory mediators and microcirculation disturbance in severe acute pancreatitis (SAP) rats and explore its therapeutic mechanism.

METHODS

The rats were randomly divided into SAP group, baicalin-treated group and sham operated group. At 3, 6, and 12 hours after operation, we examined the mortality rate of rats, ascites volume, and pancreatic pathological changes in each group and determined the contents of inflammatory mediators in blood as well as the changes in blood viscosity.

RESULTS

Compared with SAP group, treatment with baicalin is able to improve the pathological damage of the pancreas, reduce the contents of multiple inflammatory mediators in blood, decrease the amount of ascitic fluid, and reduce the mortality rates of SAP rats. The low-shear whole blood viscosity in baicalin-treated group (at 3 hours) as well as the high-shear and low-shear whole blood viscosity in baicalin-treated group (at 12 hours) were significantly lower than that in SAP group.

CONCLUSIONS

Baicalin has good prospects in the treatment for SAP because it can exert therapeutic effects on this disease through inhibiting the production of inflammatory mediators, decreasing blood viscosity, improving microcirculation, and mitigating the pathological damage of the pancreas.

Efficacy and mechanism of Salvia miltiorrhizae injection in the treatment of rats with severe acute pancreatitis

To study the efficacy and mechanism of Salvia miltiorrhizae injection in the treatment of severe acute pancreatitis. SAP rat models were prepared and randomly divided into model control group and treated group. The sham-operated group was also set. At 3, 6 and 12 h after operation, the mortality rate, ascitic volumes, pathological changes in the pancreas, contents of amylase and endotoxin in plasma as well as IL-6, IL-18, ET-1 and NO in serum, the staining intensity of Bax and NF-kappaB p56 proteins, and the changes in apoptosis index of pancreatic cells in rats in each group were observed. The pathological severity scores (at 3, 6 and 12 h after operation), contents of plasma endotoxin (at 6 and 12 h after operation) and serum IL-6 (at 6 and 12 h after operation) were significantly lower than those in model control group (P < 0.05, P < 0.01 and P < 0.01, respectively); the staining intensity and the product of the staining intensity and positive staining rate of Bax protein in the pancreas were significantly higher than those in model control group (P < 0.01). Salvia miltiorrhizae is able to reduce the contents of plasma endotoxin and serum IL-6, promote the expression of Bax protein in pancreas, improve the pathological changes in the pancreas, and decrease the mortality rate of rats, thereby showing therapeutic effect on rats with SAP.

[New perspectives in studies of the urogenital tract microcirculation--a decade of experience in Szeged, Hungary]

Investigations in microcirculation are an essential way to understand basic pathologic mechanisms and detect early signs of various diseases. Up until the last decade there was only limited amount of information available in the field of urological microcirculation. Due to advanced technologies, new methods and international cooperation of the research team of University of Szeged, promising new data became available in this interesting field.

Probability density functions for axial ratios of sectioning profiles of anisotropically arranged elliptical microvessels

The article theoretically regards probability density functions (PDFs) for axial ratio (X/Y) of sectioning profiles of elliptical microvessels (MVs) arranged with anisotropy in a biological tissue volume. A technique for the PDF(X/Y) calculations in anisotropy of the elliptical MVs is described. The essence of this technique is introducing anisotropy in PDF(alpha,phi), i.e. the function of the joint distribution of the polar and planar angles alpha and phi, which define mutual orientation of the elliptical MVs and sectioning planes. With the aid of this technique, the anisotropy cases are studied with PDF(alpha,phi) given by pair combinations of the following distributions: (i) a uniform distribution of the angles alpha and/or phi, (ii) the angle alpha distribution with PDF(alpha)=sin alpha(alpha in [0,pi/2]), and (iii) Gaussian distributions of the alpha or phi values. Specifically, PDF(X/Y) curves are obtained for MVs with the true, or three-dimensional, axial ratio X(0)/Y(0)=2.0, and the anisotropy effects on the X/Y expected frequencies are analysed. Conclusions of this analysis, the PDF(X/Y) calculation technique, and the PDF(X/Y) curves obtained are useful for stereological reconstruction of anisotropically organised microcirculatory networks, with an ellipticity of their MVs being taken into consideration.

Octreotide attenuates impaired microcirculation in postischemic pancreatitis when administered before induction of ischemia

BACKGROUND

Ischemia-reperfusion injury of the pancreas causes impairment of microcirculation leading to pancreatitis. Postischemic pancreatitis is the most common reason for graft failure in pancreas transplantation. In animal models, octreotide has been described to have beneficial effects on acute pancreatitis by reducing pancreatic enzyme release and edema formation by preventing the increase of macromolecular extravasation. In contrast to earlier experimental setups, this study investigated the influence of octreotide on ischemia-reperfusion pancreatitis when administered before induction of ischemia.

METHODS

Sprague-Dawley rats were randomly assigned to three groups: (1) sham-operated animals (sham group, n=7); (2) 1 hr ischemia followed by 1 hr reperfusion (control group, n=7); (3) administration of 50 microg/kg octreotide intravenously 15 min before ischemia (octreotide group, n=7). At the end of reperfusion, intravital fluorescence microscopy was performed assessing the functional capillary density (FCD), leukocyte-endothelium interaction (LEI), and the microvascular permeability. Finally serum amylase and lipase were measured.

RESULTS

The application of octreotide significantly reduced the ischemia-reperfusion-induced reduction of FCD (318.4+/-44.1 cm/cm vs. 257.4+/-11.7 cm/cm, P<0.001). The increase of LEI due to ischemia-reperfusion (466.9+/-52.2 cells/mm) was reduced in the octreotide group (264.4+/-55.1, P=0.001). Permeability was significantly lower in the octreotide group (0.56+/-0.57x10 cm/sec vs. 2.2.1+/-0.54x10 cm/sec, P<0.001). The level of serum lipase was reduced significantly after octreotide therapy (72.4+/-53.4 U/L vs. 136.7+/-66.5 U/L, P=0.026).

CONCLUSION

Octreotide significantly attenuated pancreatic dysfunction caused by ischemia-reperfusion when given before ischemia. Furthermore, we could prove for the first time a beneficial role of octreotide on preservation of the microvascular barrier for macromolecules.

Substance P mediates cerulein-induced pancreatic microcirculatory dysfunction in mice

OBJECTIVES

The present study was conducted to examine the contribution of substance P to the pancreatic microcirculatory dysfunction during acute pancreatitis.

METHODS

Pancreatitis was elicited by up to 6 hourly injections of cerulein (50 microg/kg IP) in male C57Bl/6 mice. At 0, 1, 3, and 6 hours after cerulein treatment, the pancreatic microvasculature in anesthetized mice was studied using established high-resolution in vivo microscopic methods.

RESULTS

Treatment of mice with cerulein for 6 hours caused a 30% decrease in capillary perfusion and the diameter of the capillaries and an increase in microvascular permeability (20%) and interstitial space (30-fold). The administration of the substance P receptor antagonist (D-Arg1, D-Pro2, D-Trp7,9, Leu11) (2 mg/kg IP) minimized the pancreatic microcirculatory dysfunction 3 hours after cerulein treatment. The superfusion of substance P for 0.5 hours decreased the diameter (by 22%) and increased microvascular permeability (by 23%) along with interstitial space (22-fold increase). Blockade of substance P receptor attenuated substance P-induced pancreatic microcirculatory dysfunction.

CONCLUSIONS

These results suggest that substance P mediates pancreatic microcirculatory dysfunction during the development of acute pancreatitis.

Targeting vascular endothelial growth factor pathway offers new possibilities to counteract microvascular disturbances during ischemia/reperfusion of the pancreas

BACKGROUND

It is of crucial importance to explore new therapeutic strategies capable of combating or even preventing pancreatic graft failure after transplantation caused by ischemia reperfusion damage. So far, the role of the hypoxia induced mediator vascular endothelial growth factor (VEGF) upon pancreatic microcirculation has not been described. Therefore the aim of this study was to investigate its influence, using the novel tyrosinekinase inhibitor PTK787/ZK222584 (PTK/ZK), upon functional capillary density (FCD), leukocyte-endothelium interaction (LEI), and macromolecular permeability (P) of normal and postischemic pancreas tissue.

METHODS

Sprague-Dawley rats were anesthetized and randomly assigned to five groups (n=7/group): (a) sham, (b) ischemia/reperfusion (I/R) control, (c) I/R and PTK/ZK treatment, (d) VEGF-superfusion, (e) VEGF-superfusion and PTK/ZK-treatment. A recently established method of digital dynamic intravital epifluorescence microscopy was used for evaluating the effective microvascular permeability together with FCD and LEI.

RESULTS

Comparison between sham vs. I/R shows a significant upregulation of VEGF-expression followed by deterioration of microcirculation with decreased FCD, increased P and LEI. Treatment with PTK/ZK resulted in a significant decrease of P under conditions of superfusion with VEGF as well as I/R compared to corresponding groups without treatment.

CONCLUSION

VEGF plays a crucial causative role involving an increase in permeability in normal as well as in postischemic pancreatitis via tyrosinkinase receptors. VEGF seems to be partly accountable for a deterioration of FCD and an upregulation of LEI via VEGF-tyrosinekinase receptor independent mechanisms. VEGF might be a promising potential therapeutic target in order to minimize edema formation caused by I/R and pancreatitis in pancreas transplantation.

Soluble complement receptor 1 preserves endothelial barrier function and microcirculation in postischemic pancreatitis in the rat

Components of the activated complement cascade are considered to play a pivotal role in ischemia-reperfusion-induced organ injury. With the use of intravital epifluorescence microscopy, we investigated the effect of complement inhibition by the recombinant soluble complement receptor 1 (sCR1; TP10) on the effect of macromolecular microvascular permeability, functional capillary perfusion, and leukocyte endothelium interaction in postischemic pancreatitis. Anaesthetized Sprague-Dawley rats were subjected to 60 min of normothermic pancreatic ischemia induced by microclipping of the blood-supplying arteries of the organ. Rats who received sCR1 (15 mg/kg body wt iv; n = 7) during reperfusion showed a significant reduction of permeability (1.77 +/- 1.34 x 10(-8) cm/s; n = 7) of tetramethylrhodamine isothiocyanate-labeled albumin injected 90 min after the onset of reperfusion compared with vehicle-treated animals (6.95 +/- 1.56 x 10(-8) cm/s; n = 7). At 120 min after the onset of reperfusion, the length of red blood cell-perfused capillaries (functional capillary density) was significantly improved (from 279 +/- 15.7 to 330 +/- 3.7 cm(-1); n = 7) and the number of leukocytes adherent to postcapillary venules was significantly reduced (from 314 +/- 87 to 163 +/- 71 mm(-2); n = 7) by sCR1 compared with vehicle treatment. Complement inhibition by sCR1 effectively ameliorates pancreatic ischemia-reperfusion-induced microcirculatory disturbances and might be considered for treatment of postischemic pancreatitis.