Argatroban administration reduces leukocyte adhesion and improves capillary perfusion within the intestinal microcirculation in experimental sepsis

2010 ◽  
Vol 104 (11) ◽  
pp. 1022-1028 ◽  
Author(s):  
Christian Fuchs ◽  
Elena Ladwig ◽  
Juan Zhou ◽  
Dragan Pavlovic ◽  
Kristina Behrend ◽  
...  
Keyword(s):  
Leukocyte Adhesion ◽  
Capillary Density ◽  
Functional Capillary Density ◽  
Experimental Sepsis ◽  
Capillary Perfusion ◽  
Vascular Contractility ◽  
Intestinal Microcirculation ◽  
Sham Surgery ◽  
The Impact

SummaryCo-activation of pro-coagulatory pathways in sepsis may result in disseminated intravascular coagulation and contributes to microvascular dysfunction. We investigated the effects of the direct thrombin inhibitor, argatroban (ARG), on the sepsis-induced impairment of the intestinal microcirculation (capillary perfusion, leukocyte adhesion) and the vascular contractility in rats. Forty male Lewis rats were randomly assigned to one of four groups: sham surgery (SHAM), experimental sepsis (colon ascendens stent peritonitis – CASP), CASP+ARG, and SHAM+ARG. At 16 hours after colon stent insertion (or sham surgery), 2 mg/kg argatroban or buffer were given intravenously, and 1 hour thereafter, intravital microscopy was performed. In addition, experiments to study the impact of ARG on vascular contractility were conducted in vitro. ARG administration in CASP rats significantly increased functional capillary density in mucosal (+128%) and muscular layers (longitudinal: +42%; circular: +64%) and decreased the number of firmly adhering leukocytes in the intestinal submucosa compared to untreated animals. In vitro findings indicated a vasodilating effect of ARG. ARG administration during experimental sepsis improved intestinal microcirculation by preserving functional capillary density, an indicator of microvascular perfusion, and by reducing leukocyte adherence to the endothelium in submucosal venules.

Dexmedetomidine Attenuates the Microcirculatory Derangements Evoked by Experimental Sepsis

2015 ◽  
Vol 122 (3) ◽  
pp. 619-630 ◽  
Author(s):  
Marcos L. Miranda ◽  
Michelle M. Balarini ◽  
Eliete Bouskela
Keyword(s):  
Blood Gases ◽  
Capillary Density ◽  
Sepsis Syndrome ◽  
In Vivo Studies ◽  
Experimental Sepsis ◽  
Leukocyte Rolling ◽  
Capillary Perfusion ◽  
Arterial Blood ◽  
Baseline Values

Abstract Background: Dexmedetomidine, an α-2 adrenergic receptor agonist, has already been used in septic patients although few studies have examined its effects on microcirculatory dysfunction, which may play an important role in perpetuating sepsis syndrome. Therefore, the authors have designed a controlled experimental study to characterize the microcirculatory effects of dexmedetomidine in an endotoxemia rodent model that allows in vivo studies of microcirculation. Methods: After skinfold chamber implantation, 49 golden Syrian hamsters were randomly allocated in five groups: (1) control animals; (2) nonendotoxemic animals treated with saline; (3) nonendotoxemic animals treated with dexmedetomidine (5.0 μg kg−1 h−1); (4) endotoxemic (lipopolysaccharide 1.0 mg/kg) animals treated with saline; and (5) endotoxemic animals treated with dexmedetomidine. Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables and venular leukocyte rolling and adhesion. Mean arterial blood pressure, heart rate, arterial blood gases, and lactate concentrations were also documented. Results: Lipopolysaccharide administration increased leukocyte rolling and adhesion and decreased capillary perfusion. Dexmedetomidine significantly attenuated these responses: compared with endotoxemic animals treated with saline, those treated with dexmedetomidine had less leukocyte rolling (11.8 ± 7.2% vs. 24.3 ± 15.0%; P < 0.05) and adhesion (237 ± 185 vs. 510 ± 363; P < 0.05) and greater functional capillary density (57.4 ± 11.2% of baseline values vs. 45.9 ± 11.2%; P < 0.05) and erythrocyte velocity (68.7 ± 17.6% of baseline values vs. 54.4 ± 14.8%; P < 0.05) at the end of the experiment. Conclusions: Dexmedetomidine decreased lipopolysaccharide-induced leukocyte–endothelial interactions in the hamster skinfold chamber microcirculation. This was accompanied by a significant attenuation of capillary perfusion deficits, suggesting that dexmedetomidine yields beneficial effects on endotoxemic animals’ microcirculation.

Hemorrhagic hypotension induces arteriolar vasomotion and intermittent capillary perfusion in rat pancreas

1994 ◽  
Vol 267 (5) ◽  
pp. H1936-H1940 ◽  
Author(s):  
B. Vollmar ◽  
G. Preissler ◽  
M. D. Menger
Keyword(s):  
Blood Cell ◽  
Microscopic Analysis ◽  
Capillary Density ◽  
Functional Capillary Density ◽  
Intravital Fluorescence Microscopy ◽  
Capillary Perfusion ◽  
Induced Hypotension ◽  
Rat Pancreas ◽  
Hemorrhagic Hypotension ◽  
Acinar Tissue

Hemorrhage-induced intermittent capillary perfusion and its relation to arteriolar vasomotion was studied in rat pancreatic acinar tissue using intravital fluorescence microscopy. During prehemorrhage conditions, microscopic analysis of the pancreatic microcirculation displayed neither arteriolar vasomotion nor intermittency of capillary perfusion (n = 22 animals). Hemorrhage-induced hypotension of 40 mmHg provoked arteriolar vasomotion in 18 of 22 animals and 59 of 115 arterioles studied. The maximum relative amplitude of arteriolar vasomotion was 44 +/- 8% (range 12–81%), and vasomotion frequency averaged 4.73 +/- 0.11 cycles/min. Hemorrhagic hypotension was further accompanied by 1) a decrease of functional capillary density [length of red blood cell-perfused capillaries per area of tissue under investigation (cm/cm2)] from 515 +/- 3 cm-1 at baseline to 386 +/- 3 cm-1 (P < 0.05) and 2) the instantaneous occurrence of intermittency of capillary perfusion in all observation areas (N = 220) of the 22 animals studied. The frequency of intermittency of capillary perfusion (4.72 +/- 0.14 cycles/min) did not differ from the frequency of arteriolar vasomotion, which implies a causal relationship between these two hemorrhage-induced microvascular mechanisms with the probable aim to counteract the decrease of functional capillary density.

The novel iron chelator, DIBI, attenuates inflammation and improves outcome in colon ascendens stent peritonitis-induced experimental sepsis

2020 ◽  
Vol 76 (2) ◽  
pp. 241-261
Author(s):  
Danielle Fokam ◽  
Maral Aali ◽  
Kayle Dickson ◽  
Cassidy Scott ◽  
Bruce Holbein ◽  
...  
Keyword(s):  
Immune Response ◽  
Leukocyte Adhesion ◽  
Bacterial Load ◽  
Systemic Infection ◽  
Lavage Fluid ◽  
Experimental Sepsis ◽  
Capillary Perfusion ◽  
Term Survival ◽  
Colon Ascendens

BACKGROUND: Sepsis is the result of a dysregulated host immune response to an infection. An ideal therapy would target both the underlying infection and the dysregulated immune response. DIBI, a novel iron-binding polymer, was specifically developed as an antimicrobial agent and has also demonstrated in vivo anti-inflammatory properties. OBJECTIVE: This study aimed to further investigate the effects of DIBI with and without the antibiotic imipenem (IMI) in colon ascendens stent peritonitis (CASP)-induced experimental sepsis. METHODS: Vehicle, DIBI and/or IMI were administered in C57BL/6 mice after CASP surgery. Intestinal leukocyte activation and capillary perfusion was evaluated by intravital microscopy. Moreover, bacterial load in peritoneal lavage fluid and blood, and plasma cytokine levels were assessed. In a second series of experiments, surgery to repair the colon was performed at 5 hr and these mice were followed for long-term survival over 7 days. RESULTS: DIBI reduced leukocyte adhesion, improved capillary blood flow, and decreased key plasma cytokines levels. DIBI also improved survival of infected mice and greatly improved IMI efficacy. Survivors treated with IMI and DIBI were found to be free of systemic infection. CONCLUSIONS: DIBI has promising potential for sepsis treatment including its use as a sole or an adjunct therapeutic with antibiotics.

Evolution of a “falx lunatica” in demarcation of critically ischemic myocutaneous tissue

2005 ◽  
Vol 288 (3) ◽  
pp. H1224-H1232 ◽  
Author(s):  
Yves Harder ◽  
Michaela Amon ◽  
Mirko Georgi ◽  
Andrej Banic ◽  
Dominique Erni ◽  
...  
Keyword(s):  
Capillary Density ◽  
Functional Capillary Density ◽  
Tissue Necrosis ◽  
Capillary Perfusion ◽  
Edema Formation ◽  
Perfusion Failure ◽  
Ischemic Tissue ◽  
Flap Elevation ◽  
Observation Period

Using intravital microscopy in a chronic in vivo mouse model, we studied the demarcation of myocutaneous flaps and evaluated microvascular determinants for tissue survival and necrosis. Chronic ischemia resulted in a transition zone, characterized by a red fringe and a distally adjacent white falx, which defined the demarcation by dividing the proximally normal from the distally necrotic tissue. Tissue survival in the red zone was determined by hyperemia, as indicated by recovery of the transiently reduced functional capillary density, and capillary remodeling, including dilation, hyperperfusion, and increased tortuosity. Angiogenesis and neovascularization were not observed over the 10-day observation period. The white rim distal to the red zone, appearing as “falx lunatica,” showed a progressive decrease of functional capillary density similar to that of the necrotic distal area but without desiccation, and thus transparency, of the tissue. Development of the distinct zones of the critically ischemic tissue could be predicted by partial tissue oxygen tension (Pt[Formula: see text]) analysis by the time of flap elevation. The falx lunatica evolved at a Pt[Formula: see text] between 6.2 ± 1.3 and 3.8 ± 0.7 mmHg, whereas tissue necrosis developed at <3.8 ± 0.7 mmHg. Histological analysis within the falx lunatica revealed interstitial edema formation and muscle fiber nuclear rarefaction but an absence of necrosis. We have thus demonstrated that ischemia-induced necrosis does not demarcate sharply from normal tissue but develops beside a fringe of tissue with capillary remodeling an adjacent falx lunatica that survives despite nutritive capillary perfusion failure, probably by direct oxygen diffusion.

Antithrombin reduces leukocyte adhesion during chronic endotoxemia by modulation of the cyclooxygenase pathway

2000 ◽  
Vol 279 (1) ◽  
pp. C98-C107 ◽  
Author(s):  
J. N. Hoffmann ◽  
B. Vollmar ◽  
D. Inthorn ◽  
F. W. Schildberg ◽  
M. D. Menger
Keyword(s):  
Endothelial Cell ◽  
Leukocyte Adhesion ◽  
Repeated Administration ◽  
Capillary Density ◽  
Cell Interaction ◽  
Multiple Organ ◽  
Microvascular Perfusion ◽  
Leukocyte Adherence ◽  
Capillary Perfusion ◽  
Endothelial Cell Interaction

Antithrombin (AT) is known as the most important natural inhibitor of thrombin activity and has been shown to improve distinct clinical parameters during the course of septic (endotoxin)-induced multiple organ dysfunction. We hypothesized that AT acts by inhibiting leukocyte activation and microvascular injury via the promotion of endothelial release of PGI2, and therefore, we studied the effects of AT on leukocyte/endothelial cell interaction and microvascular perfusion during endotoxemia. In a skinfold preparation of Syrian hamsters, severe endotoxemia was induced by repeated administration of endotoxin intravenously [lipopolysaccharide (LPS), Escherichia coli, 2 mg/kg] at 0 and 48 h. AT (250 IU/kg) was administered intravenously at 0, 24, and 48 h ( n = 6, AT group). In control animals ( n = 5, control), LPS was given without AT supplementation. By intravital fluorescence microscopy, leukocyte-endothelial cell interaction and functional capillary density (FCD; measure of capillary perfusion) were analyzed during a 72-h period after the first LPS injection. AT significantly attenuated LPS-induced arteriolar and venular leukocyte adherence after both the first and the second LPS injection [ P < 0.01, measures analysis of variance (MANOVA)]. In parallel, AT was effective in preventing LPS-induced depression of FCD after the first and the second LPS administration ( P < 0.05, MANOVA). By pretreatment with the cyclooxygenase inhibitor indomethacin ( n = 6), effects of AT on leukocyte adherence and FCD were found completely abolished. Thus our study indicates that AT exerts its beneficial effects in endotoxemia by reducing leukocyte-endothelial cell interaction and microvascular perfusion failure probably via liberation of prostacyclin from endothelial cells.

Abstract 13502: Glucagon-like Peptide-1 Directly Promotes Angiogenesis via PKA/AMPK-dependent Autophagy in Endothelial Cells

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Akio Monij ◽  
Yasuko K Bando ◽  
Morihiko Aoyama ◽  
Haruya Kawase ◽  
Toko Mitsui ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Capillary Density ◽  
Tube Formation ◽  
Catalytic Subunit ◽  
Related Gene ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
The Impact ◽  
In Vitro Angiogenesis

Introduction: We recently reported the impact of glucagon-like peptide-1 (GLP-1) on myocardial remodeling observed in type 2 diabetic mice (T2DM) via cyclic-AMP-dependent activation of autophagy in myocardium; however, it remains unclear whether GLP-1 may modulates capillary formation in heart. Hypothesis/AIM: We thus evaluated the impact of GLP-1 on angiogenesis and its link to endothelial autophagy. Methods: T2DM was treated with Ex4 (24 nmole/kg/day for 4 weeks). Cardiac capillary density was measured by immunohistology. Cultured HUVECs were used for in vitro experiments. Changes in activities of autophagy (LC3-turnover assay and protein levels of p62 and Beclin1), and angiogenesis (tube formation assay and Akt/AMPK/eNOS activity), were evaluated.[[Unable to Display Character: &#8232;]] Role of PKA was assessed by CREB phosphorylation and RNA interference (siRNA for catalytic subunit of PKA). Effect of autophagy was assessed by use of pharmacological inhibitor 3MA and siRNA of autophagy-related gene (ATG) 5 , ATG7, and p62. Results: Immunohistochemical analyses revealed that T2DM exhibited reduced cardiac capillary density, which was reversed by Ex-4 with concomitant amelioration of systemic diabetic condition. Ex-4 treated heart exhibited increase in myocardial cyclic AMP concentration. We thus observed direct impact of Ex-4 and cyclic AMP elevation on HUVECs, in which GLP-1 receptor expression was confirmed by immunoblot and QPCR. In vitro angiogenesis assay revealed that Ex-4 and PKA enhancers (10 μM forskolin and 1 mM 8-bromo-cyclic AMP) facilitated angiogenesis and autophagy in HUVECs. The PKA/AMPK/eNOS phosphorylation levels of Ex-4-treated HUVECs were elevated. Of note, each Akt activity remains unchanged. PKA inhibitors (H89, RP-cAMP, siRNA) abrogated the increase in phosphorylation of AMPK/eNOS axis induced by Ex-4 in HUVECs. Tube formation assay revealed that Ex-4 and PKA enhancers augmented in vitro angiogenesis, which were abrogated by inhibition of autophagy and AMPK using pharmacological inhibitors (3MA and compound C) and siRNA for autophagy-related gene (ATG) 5 , ATG7, p62, and catalytic subunit of AMPK. [[Unable to Display Character: &#8232;]] Conclusions: GLP-1 directly promoted angiogenesis via the PKA/AMPK-dependent autophagic activation.

scholarly journals Mdivi-1 Protects CD4+ T Cells against Apoptosis via Balancing Mitochondrial Fusion-Fission and Preventing the Induction of Endoplasmic Reticulum Stress in Sepsis

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
You Wu ◽  
Yong-Ming Yao ◽  
He-Liang Ke ◽  
Lan Ying ◽  
Yao Wu ◽  
...  
Keyword(s):  
T Cells ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Protective Effect ◽  
Mitochondrial Fusion ◽  
Mitochondrial Morphology ◽  
Experimental Sepsis ◽  
The Impact

Apoptosis of CD4+ T cells plays a central role in the progression of sepsis because it is associated with subsequent immunosuppression and the lack of specific treatment. Thus, developing therapeutic strategies to attenuate the apoptosis of CD4+ T cells in sepsis is critical. Several studies have demonstrated that Mdivi-1, which is a selective inhibitor of the dynamin-related protein 1 (Drp1), attenuates apoptosis of myocardial cells and neurons during various pathologic states. The present study revealed the impact of Mdivi-1 on the apoptosis of CD4+ T cells in sepsis and the potential underlying mechanisms. We used lipopolysaccharide (LPS) stimulation and cecal ligation and puncture (CLP) surgery as sepsis models in vitro and in vivo, respectively. Our results showed that Mdivi-1 attenuated the apoptosis of CD4+ T cells both in vitro and in vivo. The potential mechanism underlying the protective effect of Mdivi-1 involved Mdivi-1 reestablishing mitochondrial fusion-fission balance in sepsis, as reflected by the expression of the mitofusin 2 (MFN2) and optic atrophy 1 (OPA1) , Drp1 translocation, and mitochondrial morphology, as observed by electron microscopy. Moreover, Mdivi-1 treatment reduced reactive oxygen species (ROS) production and prevented the induction of endoplasmic reticulum stress (ERS) and associated apoptosis. After using tunicamycin to activate ER stress, the protective effect of Mdivi-1 on CD4+ T cells was reversed. Our results suggested that Mdivi-1 ameliorated apoptosis in CD4+ T cells by reestablishing mitochondrial fusion-fission balance and preventing the induction of endoplasmic reticulum stress in experimental sepsis.

scholarly journals Reduced uterine perfusion pressure decreases functional capillary density in skeletal muscle

2015 ◽  
Vol 309 (12) ◽  
pp. H2002-H2007 ◽  
Author(s):  
Graham M. Fraser ◽  
Jude S. Morton ◽  
Sydney M. Schmidt ◽  
Stephane Bourque ◽  
Sandra T. Davidge ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Continuous Flow ◽  
Perfusion Pressure ◽  
Capillary Density ◽  
Functional Capillary Density ◽  
Stopped Flow ◽  
Sprague Dawley ◽  
Capillary Perfusion ◽  
Pregnant State ◽  
Uterine Perfusion

The purpose of this study was to examine the functional and structural capillary density in the reduced uterine perfusion pressure (RUPP) model, which when performed during pregnancy is an established animal model of preeclampsia. We hypothesized that the RUPP model would be associated with capillary rarefaction and impaired capillary perfusion, which would be more pronounced in the pregnant state. Female Sprague-Dawley rats ( n = 32) were randomized to nonpregnancy (Nonpregnant) or breeding (Pregnant) at 12 wk of age and again to RUPP or SHAM surgeries on gestational day (GD) 14 (or equivalent age in nonpregnant rats). On GD 20 (or equivalent), capillary structure and perfusion of the extensor digitorum longus were imaged using digital intravital video microscopy. Functional videos were analyzed by a blinded observer to measure capillary density, expressed as capillaries per millimeter intersecting three staggered reference lines (200 μm). Flow was scored as the percentage of capillaries having 1) continuous, 2) intermittent, or 3) stopped flow. Total capillary density was not different between groups. There was a main effect of RUPP surgery resulting in decreased continuous flow vessels ( P < 0.01) and increased stopped flow ( P < 0.01), which was driven by differences between pregnant animals (Continuous flow: pregnant SHAM 80.1 ± 7.8% vs. pregnant RUPP 67.8 ± 11.2%, P < 0.05) (Stopped flow: pregnant SHAM 8.7 ± 3.2% vs. pregnant RUPP 17.9 ± 5.7%, P < 0.01). Our results demonstrate that the RUPP surgery is associated with a decrease in functional capillary density in skeletal muscle that is more pronounced in the pregnant state, which may contribute to the vascular pathophysiology observed in preeclampsia.

scholarly journals In Vitro Entero-Capillary Barrier Exhibits Altered Inflammatory and Exosomal Communication Pattern after Exposure to Silica Nanoparticles

2019 ◽  
Vol 20 (13) ◽  
pp. 3301 ◽  
Author(s):  
Jennifer Y. Kasper ◽  
M. Iris Hermanns ◽  
Annette Kraegeloh ◽  
W. Roth ◽  
C. James Kirkpatrick ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Cell Line ◽  
Leukocyte Adhesion ◽  
Culture Conditions ◽  
Chronic Inflammatory Bowel Disease ◽  
Microvascular Endothelial Cell ◽  
Inflamed Endothelium ◽  
Model Drug ◽  
The Impact

The intestinal microvasculature (iMV) plays multiple pathogenic roles during chronic inflammatory bowel disease (IBD). The iMV acts as a second line of defense and is, among other factors, crucial for the innate immunity in the gut. It is also the therapeutic location in IBD targeting aggravated leukocyte adhesion processes involving ICAM-1 and E-selectin. Specific targeting is stressed via nanoparticulate drug vehicles. Evaluating the iMV in enterocyte barrier models in vitro could shed light on inflammation and barrier-integrity processes during IBD. Therefore, we generated a barrier model by combining the enterocyte cell line Caco-2 with the microvascular endothelial cell line ISO-HAS-1 on opposite sides of a transwell filter-membrane under culture conditions which mimicked the physiological and inflamed conditions of IBD. The IBD model achieved a significant barrier-disruption, demonstrated via transepithelial-electrical resistance (TER), permeability-coefficient (Papp) and increase of sICAM sE-selectin and IL-8. In addition, the impact of a prospective model drug-vehicle (silica nanoparticles, aSNP) on ongoing inflammation was examined. A decrease of sICAM/sE-selectin was observed after aSNP-exposure to the inflamed endothelium. These findings correlated with a decreased secretion of ICAM/E-selectin bearing exosomes/microvesicles, as evaluated via ELISA. Our findings indicate that aSNP treatment of the inflamed endothelium during IBD may hamper exosomal/microvesicular systemic communication.

Vasomotion in critically perfused muscle protects adjacent tissues from capillary perfusion failure

2000 ◽  
Vol 279 (2) ◽  
pp. H550-H558 ◽  
Author(s):  
M. Rücker ◽  
O. Strobel ◽  
B. Vollmar ◽  
F. Roesken ◽  
M. D. Menger
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Capillary Flow ◽  
Capillary Density ◽  
Functional Capillary Density ◽  
Sprague Dawley ◽  
Capillary Perfusion ◽  
Peripheral Tissues ◽  
Flow Motion ◽  
Stepwise Reduction

We analyzed the incidence and interaction of arteriolar vasomotion and capillary flow motion during critical perfusion conditions in neighboring peripheral tissues using intravital fluorescence microscopy. The gracilis and semitendinosus muscles and adjacent periosteum, subcutis, and skin of the left hindlimb of Sprague-Dawley rats were isolated at the femoral vessels. Critical perfusion conditions, achieved by stepwise reduction of femoral artery blood flow, induced capillary flow motion in muscle, but not in the periosteum, subcutis, and skin. Strikingly, blood flow within individual capillaries was decreased ( P < 0.05) in muscle but was not affected in the periosteum, subcutis, and skin. However, despite the flow motion-induced reduction of muscle capillary blood flow during the critical perfusion conditions, functional capillary density remained preserved in all tissues analyzed, including the skeletal muscle. Abrogation of vasomotion in the muscle arterioles by the calcium channel blocker felodipine resulted in a redistribution of blood flow within individual capillaries from cutaneous, subcutaneous, and periosteal tissues toward skeletal muscle. As a consequence, shutdown of perfusion of individual capillaries was observed that resulted in a significant reduction ( P < 0.05) of capillary density not only in the neighboring tissues but also in the muscle itself. We conclude that during critical perfusion conditions, vasomotion and flow motion in skeletal muscle preserve nutritive perfusion (functional capillary density) not only in the muscle itself but also in the neighboring tissues, which are not capable of developing this protective regulatory mechanism by themselves.

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