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Iwakiri Y, Groszmann RJ. The hyperdynamic circulation of chronic liver diseases: from the patient to the molecule. Hepatology 2006; 43:S121-31. [PMID: 16447289 DOI: 10.1002/hep.20993] [Citation(s) in RCA: 403] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The hyperdynamic circulatory syndrome observed in chronic liver diseases is a great example of research that originated from clinical observations and progressed in the last 50 years from the patient to the experimental laboratory. Our knowledge has evolved from the patient to the molecule, using experimental models that serve as a source for understanding the complex pathophysiological mechanisms that govern this complex syndrome. We now know that progressive vasodilatation is central to the detrimental effects observed in multiple organs. Although nitric oxide has been shown to be the primary vasodilator molecule in these effects, other molecules also participate in the complex mechanisms of vasodilatation. This review summarizes three major areas: first, clinical observation in patients; second, experimental models used to study the hyperdynamic circulatory syndrome; and third, the vasodilator molecules that play roles in vascular abnormalities observed in portal hypertension.
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Research Support, N.I.H., Extramural |
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Wilkes NJ, Woolf R, Mutch M, Mallett SV, Peachey T, Stephens R, Mythen MG. The effects of balanced versus saline-based hetastarch and crystalloid solutions on acid-base and electrolyte status and gastric mucosal perfusion in elderly surgical patients. Anesth Analg 2001; 93:811-6. [PMID: 11574338 DOI: 10.1097/00000539-200110000-00003] [Citation(s) in RCA: 359] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
UNLABELLED The IV administration of sodium chloride solutions may produce a metabolic acidosis and gastrointestinal dysfunction. We designed this trial to determine whether, in elderly surgical patients, crystalloid and colloid solutions with a more physiologically balanced electrolyte formulation, such as Hartmann's solution and Hextend, can provide a superior metabolic environment and improved indices of organ perfusion when compared with saline-based fluids. Forty-seven elderly patients undergoing major surgery were randomly allocated to one of two study groups. Patients in the Balanced Fluid group received an intraoperative fluid regimen that consisted of Hartmann's solution and 6% hetastarch in balanced electrolyte and glucose injection (Hextend). Patients in the Saline group were given 0.9% sodium chloride solution and 6% hetastarch in 0.9% sodium chloride solution (Hespan). Biochemical indices and acid-base balance were determined. Gastric tonometry was used as a reflection of splanchnic perfusion. Postoperative chloride levels demonstrated a larger increase in the Saline group than the Balanced Fluid group (9.8 vs 3.3 mmol/L, P = 0.0001). Postoperative standard base excess showed a larger decline in the Saline group than the Balanced Fluid group (-5.5 vs -0.9 mmol/L, P = 0.0001). Two-thirds of patients in the Saline group, but none in the Balanced Fluid group, developed postoperative hyperchloremic metabolic acidosis (P = 0.0001). Gastric tonometry indicated a larger increase in the CO2 gap during surgery in the Saline group compared with the Balanced Fluid group (1.7 vs 0.9 kPa, P = 0.0394). In this study, the use of balanced crystalloid and colloid solutions in elderly surgical patients prevented the development of hyperchloremic metabolic acidosis and resulted in improved gastric mucosal perfusion when compared with saline-based solutions. IMPLICATIONS This prospective, randomized, blinded trial showed that, in elderly surgical patients, the use of balanced IV solutions can prevent the development of hyperchloremic metabolic acidosis and provide better gastric mucosal perfusion compared with saline-based fluids.
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Abstract
A theoretical model has been developed to simulate blood flow through large microcirculatory networks. The model takes into account the dependence of apparent viscosity of blood on vessel diameter and hematocrit (the Fahraeus-Lindqvist effect), the reduction of intravascular hematocrit relative to the inflow hematocrit of a vessel (the Fahraeus effect), and the disproportionate distribution of red blood cells and plasma at arteriolar bifurcations (phase separation). The model was used to simulate flow in three microvascular networks in the rat mesentery with 436,583, and 913 vessel segments, respectively, using experimental data (length, diameter, and topological organization) obtained from the same networks. Measurements of hematocrit and flow direction in all vessel segments of these networks tested the validity of model results. These tests demonstrate that the prediction of parameters for individual vessel segments in large networks exhibits a high degree of uncertainty; for example, the squared coefficient of correlation between predicted and measured hematocrit of single vessel segments ranges only between 0.15 and 0.33. In contrast, the simulation of integrated characteristics of the network hemodynamics, such as the mean segment hematocrit or the distribution of blood flow velocities, is very precise. In addition, the following conclusions were derived from the comparison of predicted and measured values: 1) The low capillary hematocrits found in mesenteric microcirculatory networks as well as their heterogeneity can be explained on the basis of the Fahraeus effect and phase-separation phenomena. 2) The apparent viscosity of blood in vessels of the investigated tissue with diameters less than 15 microns is substantially higher than expected compared with measurements in glass tubes with the same diameter.
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Hall DM, Buettner GR, Oberley LW, Xu L, Matthes RD, Gisolfi CV. Mechanisms of circulatory and intestinal barrier dysfunction during whole body hyperthermia. Am J Physiol Heart Circ Physiol 2001; 280:H509-21. [PMID: 11158946 DOI: 10.1152/ajpheart.2001.280.2.h509] [Citation(s) in RCA: 322] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This work tested the hypotheses that splanchnic oxidant generation is important in determining heat tolerance and that inappropriate.NO production may be involved in circulatory dysfunction with heat stroke. We monitored colonic temperature (T(c)), heart rate, mean arterial pressure, and splanchnic blood flow (SBF) in anesthetized rats exposed to 40 degrees C ambient temperature. Heating rate, heating time, and thermal load determined heat tolerance. Portal blood was regularly collected for determination of radical and endotoxin content. Elevating T(c) from 37 to 41.5 degrees C reduced SBF by 40% and stimulated production of the radicals ceruloplasmin, semiquinone, and penta-coordinate iron(II) nitrosyl-heme (heme-.NO). Portal endotoxin concentration rose from 28 to 59 pg/ml (P < 0.05). Compared with heat stress alone, heat plus treatment with the nitric oxide synthase (NOS) antagonist N(omega)-nitro-L-arginine methyl ester (L-NAME) dose dependently depressed heme-.NO production and increased ceruloplasmin and semiquinone levels. L-NAME also significantly reduced lowered SBF, increased portal endotoxin concentration, and reduced heat tolerance (P < 0.05). The NOS II and diamine oxidase antagonist aminoguanidine, the superoxide anion scavenger superoxide dismutase, and the xanthine oxidase antagonist allopurinol slowed the rates of heme-.NO production, decreased ceruloplasmin and semiquinone levels, and preserved SBF. However, only aminoguanidine and allopurinol improved heat tolerance, and only allpourinol eliminated the rise in portal endotoxin content. We conclude that hyperthermia stimulates xanthine oxidase production of reactive oxygen species that activate metals and limit heat tolerance by promoting circulatory and intestinal barrier dysfunction. In addition, intact NOS activity is required for normal stress tolerance, whereas overproduction of.NO may contribute to the nonprogrammed splanchnic dilation that precedes vascular collapse with heat stroke.
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Kurose I, Wolf R, Grisham MB, Granger DN. Modulation of ischemia/reperfusion-induced microvascular dysfunction by nitric oxide. Circ Res 1994; 74:376-82. [PMID: 8118946 DOI: 10.1161/01.res.74.3.376] [Citation(s) in RCA: 287] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Leukocyte-endothelial cell adhesion and an altered metabolism of endothelial cell-derived nitric oxide (NO) have been implicated in the microvascular dysfunction associated with ischemia/reperfusion (I/R). The objective of this study was to determine whether NO donors can attenuate the reperfusion-induced increase in venular albumin leakage via an effect on leukocyte-endothelial cell adhesion. Leukocyte adherence and emigration as well as albumin extravasation were monitored in single postcapillary venules in rat mesentery subjected to 20 minutes of ischemia followed by 30 minutes of reperfusion. This I/R protocol elicits significant leukocyte adherence and emigration as well as a profound albumin leakage response. Superfusion of the mesenteric microcirculation with the NO donors sodium nitroprusside, spermine-NO, and SIN1 significantly reduced the I/R-induced leukocyte adherence/emigration and albumin leakage in postcapillary venules, whereas neither spermine nor the NO synthase inhibitor NG-nitro-L-arginine methyl ester affected the I/R-induced responses. Platelet-leukocyte aggregation and mast cell degranulation were also observed in the postischemic mesentery, and the responses were also attenuated by the NO donors. Plasma nitrate/nitrite levels in the superior mesenteric vein were significantly reduced by I/R. The results of this study indicate that I/R-induced microvascular dysfunction (albumin leakage) is attenuated by NO and that the protective effect of NO donors may be related to their ability to reduce leukocyte-endothelial cell and leukocyte-platelet interactions and/or mast cell degranulation.
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Martin PY, Ginès P, Schrier RW. Nitric oxide as a mediator of hemodynamic abnormalities and sodium and water retention in cirrhosis. N Engl J Med 1998; 339:533-41. [PMID: 9709047 DOI: 10.1056/nejm199808203390807] [Citation(s) in RCA: 272] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Review |
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van Wijck K, Lenaerts K, van Loon LJC, Peters WHM, Buurman WA, Dejong CHC. Exercise-induced splanchnic hypoperfusion results in gut dysfunction in healthy men. PLoS One 2011; 6:e22366. [PMID: 21811592 PMCID: PMC3141050 DOI: 10.1371/journal.pone.0022366] [Citation(s) in RCA: 247] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 06/26/2011] [Indexed: 12/13/2022] Open
Abstract
Background Splanchnic hypoperfusion is common in various pathophysiological conditions and often considered to lead to gut dysfunction. While it is known that physiological situations such as physical exercise also result in splanchnic hypoperfusion, the consequences of flow redistribution at the expense of abdominal organs remained to be determined. This study focuses on the effects of splanchnic hypoperfusion on the gut, and the relationship between hypoperfusion, intestinal injury and permeability during physical exercise in healthy men. Methods and Findings Healthy men cycled for 60 minutes at 70% of maximum workload capacity. Splanchnic hypoperfusion was assessed using gastric tonometry. Blood, sampled every 10 minutes, was analyzed for enterocyte damage parameters (intestinal fatty acid binding protein (I-FABP) and ileal bile acid binding protein (I-BABP)). Changes in intestinal permeability were assessed using sugar probes. Furthermore, liver and renal parameters were assessed. Splanchnic perfusion rapidly decreased during exercise, reflected by increased gapg-apCO2 from −0.85±0.15 to 0.85±0.42 kPa (p<0.001). Hypoperfusion increased plasma I-FABP (615±118 vs. 309±46 pg/ml, p<0.001) and I-BABP (14.30±2.20 vs. 5.06±1.27 ng/ml, p<0.001), and hypoperfusion correlated significantly with this small intestinal damage (rS = 0.59; p<0.001). Last of all, plasma analysis revealed an increase in small intestinal permeability after exercise (p<0.001), which correlated with intestinal injury (rS = 0.50; p<0.001). Liver parameters, but not renal parameters were elevated. Conclusions Exercise-induced splanchnic hypoperfusion results in quantifiable small intestinal injury. Importantly, the extent of intestinal injury correlates with transiently increased small intestinal permeability, indicating gut barrier dysfunction in healthy individuals. These physiological observations increase our knowledge of splanchnic hypoperfusion sequelae, and may help to understand and prevent these phenomena in patients.
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Research Support, Non-U.S. Gov't |
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Geirsson A, Szeto WY, Pochettino A, McGarvey ML, Keane MG, Woo YJ, Augoustides JG, Bavaria JE. Significance of malperfusion syndromes prior to contemporary surgical repair for acute type A dissection: outcomes and need for additional revascularizations. Eur J Cardiothorac Surg 2007; 32:255-62. [PMID: 17500002 DOI: 10.1016/j.ejcts.2007.04.012] [Citation(s) in RCA: 232] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 03/29/2007] [Accepted: 04/03/2007] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE The aim of this study was to assess the significance of malperfusion syndromes in patients with acute type A aortic dissection following a contemporary surgical management algorithm and the effects on morbidity, hospital mortality, and long-term survival. We believe that obliteration of the primary tear site with restoration of flow in the true aortic lumen results in decreased need for revascularization of malperfused organ systems. METHODS Our operative approach aims at replacing the entire ascending aorta, resuspension of the aortic valve with repair or replacement of the sinus segment, and routine open replacement of the arch under hypothermic circulatory arrest with retrograde cerebral perfusion with obliteration of false lumen at the distal arch/proximal descending thoracic aorta, thus reestablishing normal flow in the descending thoracic true lumen. From January 1993 to December 2004, 221 consecutive patients underwent repair of acute type A aortic dissection at our institution. Data were collected retrospectively and prospectively. Various types of malperfusion syndromes were present in 26.7% of patients. The organ systems with malperfusion were as follows: cardiac, 7.2%; cerebral, 7.2%; ileofemoral, 12.7%; renal, 4.1%; mesenteric, 1.4%; innominate, 5.4%; and spine, 2.2%. RESULTS Coronary malperfusion required coronary revascularization in 62.5% of cases. Distal revascularization was needed in 42.9% of patients with ileofemoral malperfusion. Patients with malperfusion were more likely to suffer perioperative myocardial infarction (p<0.001), postoperative coma (p=0.012), delirium (p=0.011), sepsis (p=0.006), acute renal failure (p=0.017), dialysis (p=0.018), and acute limb ischemia (p<0.001). The in-hospital mortality was 30.5% in patients presenting with any malperfusion syndrome while only 6.2% in patients without malperfusion syndrome (p<0.001). Both cardiac (p=0.020) and cerebral malperfusions (p<0.001) were risk factors for in-hospital mortality. The actuarial long-term survival in patients with malperfusion syndrome was estimated by Kaplan-Meier methods to be 67.8%+/-6.1% at 1 year, 54.0%+/-7.0% at 5 years, and 43.1%+/-8.0% at 10 years and for patient without malperfusion 82.7%+/-3.0% at 1 year, 66.3%+/-3.9% at 5 years, and 46.1%+/-6.7% at 10 years (log rank 2.55, p=0.110). Cerebral malperfusion was a significant risk factor for decreased long-term survival (p=0.0002). CONCLUSIONS The occurrence of malperfusion in patients with acute type A dissection is associated with significant increased risk of in-hospital mortality and complications. Additional revascularization is generally needed in patients with coronary malperfusion and ileofemoral malperfusion. Patients presenting with cardiac and cerebral malperfusions have a high hospital mortality and preoperative cerebral malperfusion is associated with dismal long-term survival.
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Moore EE, Moore FA, Franciose RJ, Kim FJ, Biffl WL, Banerjee A. The postischemic gut serves as a priming bed for circulating neutrophils that provoke multiple organ failure. THE JOURNAL OF TRAUMA 1994; 37:881-7. [PMID: 7996599 DOI: 10.1097/00005373-199412000-00002] [Citation(s) in RCA: 223] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Our trauma research center program entitled, "Trauma Primes Cells" is based on the fundamental hypothesis that prior exposure to multiple, sequential, sublethal cellular insults primes constructive or destructive pathways of cellular responses of subsequent injury. A major objective is to design therapy that will reduce the incidence of multiple organ failure. Although a number of inflammatory cascades have been incriminated in the pathogenesis of multiple organ failure (MOF), diffuse PMN-mediated tissue injury remains an attractive unifying concept. We have developed a sequential insult rodent model in which the priming event consisted of superior mesenteric arterial (SMA) clamping for 45 minutes followed by 6 hours of reperfusion. Following this priming event, activation was induced with a low dose of endotoxin (2.5 mg/kg). We believe that these studies support our hypothesis: mesenteric ischemic/reperfusion primes circulating PMNs. When these have been activated they can then be provoked by endotoxin to provoke distant organ injury. Primed PMNs are released from the postischemic mesenteric bed and enter the systemic circulation. They subsequently sequester in the pulmonary vascular bed where they are relatively harmless until they are activated by low dose endotoxin. These activated PMNs then migrate across the endothelium cell and release reactive oxygen metabolites.
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Review |
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Abstract
Despite intensive investigation, the pathogenesis of postinjury multiple organ failure (MOF) remains elusive. Laboratory and clinical research strongly implicate that the gastrointestinal tract plays a pivotal role. Shock with resulting gut hypoperfusion appears to be one important inciting event. While early studies persuasively focused attention on bacterial translocation as a unifying mechanism to explain early and late sepsis syndromes that characterize postinjury MOF, subsequent studies suggest that other gut-specific mechanisms are operational. Based on our Trauma Research Center observations and those of others, we conclude that: 1) bacterial translocation may contribute to early refractory shock; 2) for patients who survive shock, the reperfused gut appears to be a source of proinflammatory mediators that may amplify the early systemic inflammatory response syndrome; and 3) early gut hypoperfusion sets the stage for progressive gut dysfunction such that the gut becomes a reservoir for pathogens and toxins that contribute to late MOF.
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Minson CT, Wladkowski SL, Cardell AF, Pawelczyk JA, Kenney WL. Age alters the cardiovascular response to direct passive heating. J Appl Physiol (1985) 1998; 84:1323-32. [PMID: 9516200 DOI: 10.1152/jappl.1998.84.4.1323] [Citation(s) in RCA: 200] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
During direct passive heating in young men, a dramatic increase in skin blood flow is achieved by a rise in cardiac output (Qc) and redistribution of flow from the splanchnic and renal vascular beds. To examine the effect of age on these responses, seven young (Y; 23 +/- 1 yr) and seven older (O; 70 +/- 3 yr) men were passively heated with water-perfused suits to their individual limit of thermal tolerance. Measurements included heart rate (HR), Qc (by acetylene rebreathing), central venous pressure (via peripherally inserted central catheter), blood pressures (by brachial auscultation), skin blood flow (from increases in forearm blood flow by venous occlusion plethysmography), splanchnic blood flow (by indocyanine green clearance), renal blood flow (by p-aminohippurate clearance), and esophageal and mean skin temperatures. Qc was significantly lower in the older than in the young men (11.1 +/- 0.7 and 7.4 +/- 0.2 l/min in Y and O, respectively, at the limit of thermal tolerance; P < 0. 05), despite similar increases in esophageal and mean skin temperatures and time to reach the limit of thermal tolerance. A lower stroke volume (99 +/- 7 and 68 +/- 4 ml/beat in Y and O, respectively, P < 0.05), most likely due to an attenuated increase in inotropic function during heating, was the primary factor for the lower Qc observed in the older men. Increases in HR were similar in the young and older men; however, when expressed as a percentage of maximal HR, the older men relied on a greater proportion of their chronotropic reserve to obtain the same HR response (62 +/- 3 and 75 +/- 4% maximal HR in Y and O, respectively, P < 0.05). Furthermore, the older men redistributed less blood flow from the combined splanchnic and renal circulations at the limit of thermal tolerance (960 +/- 80 and 720 +/- 100 ml/min in Y and O, respectively, P < 0. 05). As a result of these combined attenuated responses, the older men had a significantly lower increase in total blood flow directed to the skin.
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Berzigotti A, Seijo S, Reverter E, Bosch J. Assessing portal hypertension in liver diseases. Expert Rev Gastroenterol Hepatol 2013; 7:141-55. [PMID: 23363263 DOI: 10.1586/egh.12.83] [Citation(s) in RCA: 197] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Portal hypertension is a common complication of chronic liver diseases and is responsible for most clinical consequences of cirrhosis, which represent the more frequent causes of death and liver transplantation in these patients. This review is aimed at clarifying the state-of-the art assessment of portal hypertension and at discussing recent developments in this field. Particular attention is paid to new noninvasive techniques that will be soon available for potential routine use.
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Review |
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Cooper ME, Bonnet F, Oldfield M, Jandeleit-Dahm K. Mechanisms of diabetic vasculopathy: an overview. Am J Hypertens 2001; 14:475-86. [PMID: 11368471 DOI: 10.1016/s0895-7061(00)01323-6] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Diabetes is commonly associated with both microvascular and macrovascular complications. These vascular complications are accelerated in the context of systemic hypertension. During the past few years the underlying molecular mechanisms responsible for diabetic vascular complications have begun to be clarified. It appears that both metabolic and hemodynamic factors interact to stimulate the expression of cytokines and growth factors in the various vascular trees. Overexpression of the prosclerotic cytokine transforming growth factor-beta has been observed in glomeruli and tubules from the diabetic kidney. In the retina the angiogenic cytokine vascular endothelial growth factor and its receptor, vascular endothelial growth factor R-2 are increased in experimental diabetes. These changes in growth factors are viewed to be responsible for the extracellular matrix accumulation in the diabetic kidney and new vessel formation in the diabetic retina. Changes in cytokines have also been observed at other vascular sites including the mesenteric vascular tree. Vasoactive hormones, such as angiotensin II and endothelin, are potent stimulators of cytokines with recent studies showing that inhibitors of these vasoactive hormone pathways may confer organ protection in diabetes by inhibition of growth factor expression. Glucose-dependent factors, such as the formation of advanced glycation end products that interact with specific receptors and lead to overexpression of a range of cytokines, may play an important role in diabetic vascular complications including atherosclerosis. It is likely that the effects of inhibitors of this pathway such as aminoguanidine on cytokine production may play a pivotal role in mediating the renal, retinal, and vasoprotective effects observed with this agent in experimental diabetes. It is anticipated that the advent of specific inhibitors of cytokine formation or action will provide new approaches for the prevention and treatment of diabetic vascular complications.
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Review |
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De Gottardi A, Trebicka J, Klinger C, Plessier A, Seijo S, Terziroli B, Magenta L, Semela D, Buscarini E, Langlet P, Görtzen J, Puente A, Müllhaupt B, Navascuès C, Nery F, Deltenre P, Turon F, Engelmann C, Arya R, Caca K, Peck-Radosavljevic M, Leebeek FWG, Valla D, Garcia-Pagan JC. Antithrombotic treatment with direct-acting oral anticoagulants in patients with splanchnic vein thrombosis and cirrhosis. Liver Int 2017; 37:694-699. [PMID: 27778440 DOI: 10.1111/liv.13285] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 10/18/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Direct-acting oral anticoagulants (DOACs) are used in patients with splanchnic vein thrombosis (SVT) and cirrhosis, but evidence for safety and efficacy in this setting is limited. Our aim was to identify indications and reasons for starting or switching to DOACs and to report adverse effects, complications and short-term outcome. METHODS Data collection including demographic information, laboratory values, treatment and complications through the Vascular Liver Disease Interest Group Consortium. RESULTS Forty-five centres (90%) of the consortium completed the initial eCRF. We report here a series of 94 patients from 17 centres. Thirty-six patients (38%) had cirrhosis. Child-Pugh score was 6 (range 5-8), and MELD score 10.2 (range 6-19). Indications for anticoagulation were splanchnic vein thrombosis (75%), deep vein thrombosis (5%), atrial fibrillation (14%) and others (6%). DOACs used were rivaroxaban (83%), dabigatran (11%) and apixaban (6%). Patients were followed up for a median duration of 15 months (cirrhotic) and 26.5 months (non-cirrhotic). Adverse events occurred in 17% of patients and included one case of recurrent portal vein thrombosis and five cases of bleeding. Treatment with DOACs was stopped in three cases. The major reasons for choosing DOACs were no need for monitoring or inadequacy of INR to guide anticoagulation in cirrhotic patients. Renal and liver function did not change during treatment. CONCLUSIONS A consistent number of patients with SVT and/or cirrhosis are currently treated with DOACs, which seem to be effective and safe. These data provide a basis for performing randomized clinical trials of DOACs vs. low molecular weight heparin or vitamin K antagonists.
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Multicenter Study |
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Ley K, Gaehtgens P. Endothelial, not hemodynamic, differences are responsible for preferential leukocyte rolling in rat mesenteric venules. Circ Res 1991; 69:1034-41. [PMID: 1934331 DOI: 10.1161/01.res.69.4.1034] [Citation(s) in RCA: 173] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
At the onset of the inflammatory process, leukocytes roll along venular but not arteriolar walls before they firmly attach and emigrate. To test whether differences in hydrodynamic flow conditions are responsible for the preferential occurrence of leukocyte rolling in venules, we varied wall shear rate, gamma w, between 30 and 2,000 sec-1 by selective micro-occlusion of side branches in venules and arterioles (diameter, 20-37 microns) of the exposed mesentery of anesthetized rats. In venules, 39% (range, 6-77%) of all passing leukocytes were found interacting with the endothelium (rolling), whereas this fraction was only 0.6% in arterioles. The fraction of rolling leukocytes in venules decreased from 49 +/- 13% at gamma w less than 100 sec-1 (N = 12) to 24 +/- 13% at gamma w greater than 400 sec-1 (N = 12). Mean leukocyte rolling velocity in venules increased with gamma w, but the most frequent rolling velocity class was 20-40 microns/sec at all shear rates. In arterioles, even prolonged (up to 90 minutes) conditions of reduced flow (gamma w less than 150 sec-1) did not induce leukocyte rolling. Radial distribution of freely flowing leukocytes not different in arterioles and venules. The data indicate that hemodynamic factors are not responsible for the difference of leukocyte adhesion between arterioles and venules. The venular endothelium appears to be specialized to support leukocyte adhesion during inflammation. This finding correlates with reports on preferential expression of various endothelial-leukocyte adhesion molecules on venular endothelial cells.
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Pizcueta MP, Piqué JM, Bosch J, Whittle BJ, Moncada S. Effects of inhibiting nitric oxide biosynthesis on the systemic and splanchnic circulation of rats with portal hypertension. Br J Pharmacol 1992; 105:184-90. [PMID: 1596680 PMCID: PMC1908593 DOI: 10.1111/j.1476-5381.1992.tb14233.x] [Citation(s) in RCA: 167] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
1. The effects of inhibiting endogenous nitric oxide (NO) synthesis with NG-monomethyl-L-arginine (L-NMMA) on the systemic and splanchnic circulation have been investigated in rats with experimental chronic portal hypertension, anaesthetized with ketamine. 2. Portal hypertension was induced by partial portal vein ligation, 2 weeks prior to study. This procedure induced a reduction in systemic arterial blood pressure (MAP), an increase in cardiac output as measured by radiolabelled microspheres, a reduction in peripheral and splanchnic vascular resistance and an increased portal venous inflow (PVI) and portal pressure, as compared to control non-ligated rats. 3. L-NMAA (6.25 and 50 mg kg-1, i.v.) dose-dependently increased MAP, reduced cardiac output and PVI, and increased peripheral and splanchnic vascular resistance. With L-NMMA (50 mg kg-1), PVI and the vascular resistances returned to values comparable to those determined in control non-ligated anaesthetized rats under resting conditions. 4. Porto-collateral resistance was also increased by these doses of L-NMMA, whereas portal pressure was unchanged. The increase in renal blood flow and decrease in renal vascular resistance also seen in portal-hypertensive rats was reversed by L-NMMA (50 mg kg-1). 5. These effects of L-NMMA (50 mg kg-1) were inhibited by prior administration of L-arginine (300 mg kg-1, i.v.). 6. These findings indicate that the chronic hyperdynamic circulatory characteristics following portal vein stenosis can be attenuated by L-NMMA. Thus, the excessive formation of endogenous NO may be implicated in the pathogenesis of the haemodynamic disturbances and splanchnic vasodilatation associated with chronic portal hypertension.
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Olde Damink SWM, Jalan R, Redhead DN, Hayes PC, Deutz NEP, Soeters PB. Interorgan ammonia and amino acid metabolism in metabolically stable patients with cirrhosis and a TIPSS. Hepatology 2002; 36:1163-71. [PMID: 12395326 DOI: 10.1053/jhep.2002.36497] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ammonia is central to the pathogenesis of hepatic encephalopathy. This study was designed to determine the quantitative dynamics of ammonia metabolism in patients with cirrhosis and previous treatment with a transjugular intrahepatic portosystemic stent shunt (TIPSS). We studied 24 patients with cirrhosis who underwent TIPSS portography. Blood was sampled and blood flows were measured across portal drained viscera, leg, kidney, and liver, and arteriovenous differences across the spleen and the inferior and superior mesenteric veins. The highest amount of ammonia was produced by the portal drained viscera. The kidneys also produced ammonia in amounts that equaled total hepatosplanchnic area production. Skeletal muscle removed more ammonia than the cirrhotic liver. The amount of nitrogen that was taken up by muscle in the form of ammonia was less than the glutamine that was released. The portal drained viscera consumed glutamine and produced ammonia, alanine, and citrulline. Urea was released in the splenic and superior mesenteric vein, contributing to whole-body ureagenesis in these cirrhotic patients. In conclusion, hyperammonemia in metabolically stable, overnight-fasted patients with cirrhosis of the liver and a TIPSS results from portosystemic shunting and renal ammonia production. Skeletal muscle removes more ammonia from the circulation than the cirrhotic liver. Muscle releases excessive amounts of the nontoxic nitrogen carrier glutamine, which can lead to ammonia production in the portal drained viscera (PDV) and kidneys. Urinary ammonia excretion and urea synthesis appear to be the only way to remove ammonia from the body.
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Yamamoto Y, Imaeda K, Suzuki H. Endothelium-dependent hyperpolarization and intercellular electrical coupling in guinea-pig mesenteric arterioles. J Physiol 1999; 514 ( Pt 2):505-13. [PMID: 9852331 PMCID: PMC2269064 DOI: 10.1111/j.1469-7793.1999.505ae.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
1. Using the conventional whole-cell clamp method, the electrical responses of individual smooth muscle and endothelial cells to acetylcholine (ACh) were observed in multicellular preparations where the two types of cells remained in close apposition. 2. In both types of cells, ACh induced similar hyperpolarizing responses which, when recorded in current clamp mode, had two phases (an initial fast and a second slower phase). 3. After blocking gap junctions, including myoendothelial junctions, with 18beta-glycyrrhetinic acid, ACh induced an outward current with two phases in voltage-clamped endothelial cells. The outward current appeared around -90 mV and increased linearly with the membrane depolarization. 4. In smooth muscle cells, ACh failed to induce a membrane current after gap junctions had been blocked with 18beta-glycyrrhetinic acid. The inhibition of ACh-induced response by 18beta-glycyrrhetinic acid was observed using either sharp or patch electrodes. 5. Nominally Ca2+-free solution reduced the initial phase and abolished the second phase of ACh-induced responses of endothelial cells. Both phases were also reduced by charybdotoxin (CTX). 6. Our results indicate that in guinea-pig mesenteric arterioles, ACh hyperpolarizes endothelial cells by activating Ca2+-activated K+ channels which are sensitive to CTX. On the other hand, hyperpolarizing responses detected in smooth muscle cells seem to originate in endothelial cells and conduct to the muscle layer via myoendothelial gap junctions.
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Abstract
The gut flora plays an important role in the pathogenesis of the complications of cirrhosis. Cirrhotic patients are prone to develop bacterial infections, mainly the 'spontaneous' infection of ascites or spontaneous bacterial peritonitis. Other complications of cirrhosis, such as variceal haemorrhage and ascites, occur mostly or solely as a consequence of portal hypertension. Portal pressure increases initially as a consequence of an increased intrahepatic resistance but, once collaterals have formed, high portal pressure is maintained by an increased splanchnic blood inflow secondary to vasodilatation. Splanchnic vasodilatation is the initiating event in the hyperdynamic circulatory state that aggravates the complications of cirrhosis. The gut flora plays a role in both the development of infections and in the hyperdynamic circulatory state of cirrhosis and, although less prominently, it also plays a role in the pathogenesis of hepatic encephalopathy. This chapter presents evidence regarding gut flora and its modification in the pathogenesis and management of these complications of cirrhosis.
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Bosch J, Abraldes JG, Fernández M, García-Pagán JC. Hepatic endothelial dysfunction and abnormal angiogenesis: new targets in the treatment of portal hypertension. J Hepatol 2010; 53:558-67. [PMID: 20561700 DOI: 10.1016/j.jhep.2010.03.021] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 03/19/2010] [Accepted: 03/19/2010] [Indexed: 12/12/2022]
Abstract
Portal hypertension is the main cause of complications in patients with chronic liver disease. Over the past 25 years, progress in the understanding of the pathophysiology of portal hypertension was followed by the introduction of an effective pharmacological therapy, consisting mainly of treatments aimed at correcting the increased splanchnic blood flow. It is only recently that this paradigm has been changed. Progress in our knowledge of the mechanisms of increased resistance to portal blood flow, of the formation of portal-systemic collaterals, and of mechanisms other than vasodilatation maintaining the increased splanchnic blood flow have opened entirely new perspectives for developing more effective treatment strategies. This is the aim of the current review, which focuses on: (a) the modulation of hepatic vascular resistance by correcting the increased hepatic vascular tone due to hepatic endothelial dysfunction, and (b) correcting the abnormal angiogenesis associated with portal hypertension, which contributes to liver inflammation and fibrogenesis, to the hyperkinetic splanchnic circulation, and to the formation of portal-systemic collaterals and varices.
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Lopez-Talavera JC, Merrill WW, Groszmann RJ. Tumor necrosis factor alpha: a major contributor to the hyperdynamic circulation in prehepatic portal-hypertensive rats. Gastroenterology 1995; 108:761-7. [PMID: 7875478 DOI: 10.1016/0016-5085(95)90449-2] [Citation(s) in RCA: 148] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND/AIMS Portal hypertension is often accompanied by a hyperdynamic circulatory syndrome. Tumor necrosis factor (TNF) alpha causes vasodilatation and a hyperdynamic state in mammals by activating nitric oxide synthesis. The aim of this study was to investigate whether TNF-alpha plays a role in developing the hyperdynamic syndrome in portal hypertension. METHODS Portal-hypertensive rats, induced by partial ligation of the portal vein (PVL), were used. In experiment 1, rats that underwent PVL were treated with polyclonal anti-mouse TNF-alpha or placebo intravenously the same day of the PVL operation and 24 hours before hemodynamic studies. Hemodynamic studies were performed 5 days after PVL. In experiment 2, rats that underwent PVL received anti-TNF-alpha or placebo intravenously 3 days and 24 hours before hemodynamics as in experiment 1. Hemodynamics were performed 14 days after the PVL operation. TNF-alpha blood levels were measured using a bioassay. RESULTS Anti-TNF-alpha treatment induced a significant increase in mean arterial pressure, heart rate, and systemic vascular resistance and a significant decrease in cardiac index, portal pressure, and TNF-alpha levels in comparison with placebo animals. No significant effects were observed in sham rats. CONCLUSIONS Anti-TNF-alpha treatment in rats that underwent PVL significantly blunts the development of the hyperdynamic circulation and reduces portal pressure. TNF-alpha may play a role in the hemodynamic abnormalities of portal hypertension.
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Horowitz M. From molecular and cellular to integrative heat defense during exposure to chronic heat. Comp Biochem Physiol A Mol Integr Physiol 2002; 131:475-83. [PMID: 11867273 DOI: 10.1016/s1095-6433(01)00500-1] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heat acclimation induces adaptive changes that improve the ability to cope with extreme environmental heat. Acclimatory homeostasis is manifested by an expanded dynamic thermoregulatory span (TRS), reflected in the intact organism by a lower temperature threshold (T(sh)) for heat dissipation, and delayed T(sh) for thermal injury. This principle shares common adaptive features with each of the thermoregulatory effectors. In the splanchnic circulation, e.g. the TRS of the thermally induced vasomotor response increases due to greater cardiac output distribution to the splanchnic vasculature, thereby increasing circulatory reserves and delaying thermal injury. During short-term heat acclimation (STHA), accelerated autonomic excitability plays a major role in the control of body temperature. Acclimatory homeostasis, however, is achieved only following long-term heat acclimation (LTHA), and is characterized by increased thermal effector efficiency, namely [effector organ output/autonomic signal] ratio >1. Two acclimatory responses, derived from our data on the acclimating rat model, are discussed: (1) acclimation of the cholinergic-muscarinic signaling for water secretion in the submaxillary gland; and (2) acclimatory mechanisms for increased contractile efficiency in the heart. Our data indicate that increased efficiency upon LTHA develops by reprogramming of gene expression. A reduced thyroid hormone level is responsible for some of the molecular adaptive cascades. Delayed thermal injury observed upon acclimation is due to enhanced cytoprotective mechanisms of which the inducible heat shock protein (HSP) 72 kDa plays a major role. Our data indicate that heat acclimation predisposes the HSP molecular machinery to respond faster and increases the constitutive level of the protein. STHA is the time-window during which most LTHA adaptations are switched on.
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Forgione MA, Weiss N, Heydrick S, Cap A, Klings ES, Bierl C, Eberhardt RT, Farber HW, Loscalzo J. Cellular glutathione peroxidase deficiency and endothelial dysfunction. Am J Physiol Heart Circ Physiol 2002; 282:H1255-61. [PMID: 11893559 DOI: 10.1152/ajpheart.00598.2001] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cellular glutathione peroxidase (GPx-1) is the most abundant intracellular isoform of the GPx antioxidant enzyme family. In this study, we hypothesized that GPx-1 deficiency directly induces an increase in vascular oxidant stress, with resulting endothelial dysfunction. We studied vascular function in a murine model of homozygous deficiency of GPx-1 (GPx-1(-/-)). Mesenteric arterioles of GPx-1(-/-) mice demonstrated paradoxical vasoconstriction to beta-methacholine and bradykinin, whereas wild-type (WT) mice showed dose-dependent vasodilation in response to both agonists. One week of treatment of GPx-1(-/-) mice with L-2-oxothiazolidine-4-carboxylic acid (OTC), which increases intracellular thiol pools, resulted in restoration of normal vascular reactivity in the mesenteric bed of GPx-1(-/-) mice. We observed an increase of the isoprostane iPF(2alpha)-III, a marker of oxidant stress, in the plasma and aortas of GPx-1(-/-) mice compared with WT mice, which returned toward normal after OTC treatment. Aortic sections from GPx-1(-/-) mice showed increased binding of an anti-3-nitrotyrosine antibody in the absence of frank vascular lesions. These findings demonstrate that homozygous deficiency of GPx-1 leads to impaired endothelium-dependent vasodilator function presumably due to a decrease in bioavailable nitric oxide and to increased vascular oxidant stress. These vascular abnormalities can be attenuated by increasing bioavailable intracellular thiol pools.
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Wiest R, Groszmann RJ. Nitric oxide and portal hypertension: its role in the regulation of intrahepatic and splanchnic vascular resistance. Semin Liver Dis 2000; 19:411-26. [PMID: 10643626 DOI: 10.1055/s-2007-1007129] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In recent years it has become well established that nitric oxide (NO) plays a crucial role in the hemodynamic abnormalities that develop in chronic portal hypertension. The purpose of this review is to summarize the available data and current concepts regarding the involvement of NO in the pathophysiologic changes in the micro-circulation of the liver and the splanchnic and systemic circulation that associate portal hypertension.
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