heparitin-sulfate and Reperfusion-Injury

The damage of the endothelial glycocalyx as a consequence of ischemia and/or reperfusion injury (IRI) following kidney transplantation has come at the spotlight of research due to potential associations with delayed graft function, acute rejection as well as long-term allograft dysfunction. The disintegration of the endothelial glycocalyx induced by IRI is the crucial event which exposes the denuded endothelial cells to further inflammatory and oxidative damage. The aim of our review is to present the currently available data regarding complex links between shedding of the glycocalyx components, like syndecan-1, hyaluronan, heparan sulphate, and CD44 with the activation of intricate immune system responses, including toll-like receptors, cytokines and pro-inflammatory transcription factors. Evidence on modes of protection of the endothelial glycocalyx and subsequently maintenance of endothelial permeability as well as novel nephroprotective molecules such as sphingosine-1 phosphate (S1P), are also depicted. Although advances in technology are making the visualization and the analysis of the endothelial glycocalyx possible, currently available evidence is mostly experimental. Ongoing progress in understanding the complex impact of IRI on the endothelial glycocalyx, opens up a new era of research in the field of organ transplantation and clinical studies are of utmost importance for the future.

Topics: Endothelium; Glycocalyx; Heparitin Sulfate; Humans; Hyaluronic Acid; Ischemia; Kidney; Kidney Transplantation; Lysophospholipids; Reperfusion Injury; Sphingosine

The endothelial glycocalyx has a profound influence at the vascular wall on the transmission of shear stress, on the maintenance of a selective permeability barrier and a low hydraulic conductivity, and on attenuating firm adhesion of blood leukocytes and platelets. Major constituents of the glycocalyx, including syndecans, heparan sulphates and hyaluronan, are shed from the endothelial surface under various acute and chronic clinical conditions, the best characterized being ischaemia and hypoxia, sepsis and inflammation, atherosclerosis, diabetes, renal disease and haemorrhagic viral infections. Damage has also been detected by in vivo microscopic techniques. Matrix metalloproteases may shed syndecans and heparanase, released from activated mast cells, cleaves heparan sulphates from core proteins. According to new data, not only hyaluronidase but also the serine proteases thrombin, elastase, proteinase 3 and plasminogen, as well as cathepsin B lead to loss of hyaluronan from the endothelial surface layer, suggesting a wide array of potentially destructive conditions. Appropriately, pharmacological agents such as inhibitors of inflammation, antithrombin and inhibitors of metalloproteases display potential to attenuate shedding of the glycocalyx in various experimental models. Also, plasma components, especially albumin, stabilize the glycocalyx and contribute to the endothelial surface layer. Though symptoms of the above listed diseases and conditions correlate with sequelae expected from disturbance of the endothelial glycocalyx (oedema, inflammation, leukocyte and platelet adhesion, low reflow), therapeutic studies to prove a causal connection have yet to be designed. With respect to studies on humans, some clinical evidence exists for benefits from application of sulodexide, a preparation delivering precursors of the glycocalyx constituent heparan sulphate. At present, the simplest option for protecting the glycocalyx seems to be to ensure an adequate level of albumin. However, also in this case, definite proof of causality needs to be delivered.

Topics: Animals; Anti-Inflammatory Agents; Endothelium, Vascular; Enzyme Inhibitors; Glycocalyx; Glycosaminoglycans; Heparitin Sulfate; Humans; Hyaluronic Acid; Peptide Hydrolases; Renal Insufficiency; Reperfusion Injury; Sepsis; Serum Albumin; Syndecans

The transplantation of tissues and organs between individuals of different species, that is, xenotransplantation, engenders a variety of immune responses. Xenogeneic immune responses mediated by naturally-occurring antibodies and complement lead to hyperacute and acute vascular rejection of vascularized organ grafts and may also cause vascular rejection of cell and tissue grafts. Under some circumstances, however, a vascularized organ graft may evade humoral rejection despite the presence of anti-donor antibodies in the circulation of the recipient; this condition is called accommodation. Xenogeneic immune responses mediated by T lymphocytes and natural killer cells may cause acute cellular rejection. The extent to which cellular rejection of xenografts resembles cellular rejection of allografts remains to be determined. New insights into the molecular mechanisms underlying the immune responses to xenotransplantation has shed light on the pathogenesis of immunological disease and has allowed the development of specific immunomodulatory strategies that may facilitate clinical application of xenotransplantation.

Topics: Animals; Antigen-Antibody Reactions; Complement Activation; Complement System Proteins; Graft Rejection; Graft Survival; Growth Substances; Heparitin Sulfate; Humans; Killer Cells, Natural; Neovascularization, Physiologic; Reperfusion Injury; Species Specificity; T-Lymphocytes; Time Factors; Transplantation, Heterologous

The glycocalyx layer is a key structure in the endothelium. Tourniquet-induced ischemic periods are used during orthopedic surgery, and the reactive oxygen species generated after ischemia-reperfusion may mediate the shedding of the glycocalyx. Here, we describe the effects of tourniquet-induced ischemia-reperfusion and compare the effects of sevoflurane and propofol on the release of endothelial biomarkers after ischemia-reperfusion in knee-ligament surgery.. This pilot, single-center, blinded, randomized, controlled trial included 16 healthy patients. After spinal anesthesia, hypnosis was achieved with sevoflurane or propofol according to randomization. During the perioperative period, five venous blood samples were collected for quantification of syndecan-1, heparan sulfate, and thrombomodulin from blood serum by using ELISA assays kits. Sample size calculation was performed to detect a 25% change in the mean concentration of syndecan-1 with an alpha of 0.05 and power of 80%.. For our primary outcome, a two-way ANOVA with post-hoc Bonferroni correction analysis showed no differences in syndecan-1 concentrations between the sevoflurane and propofol groups at any time point. In the sevoflurane group, we noted an increase in syndecan-1 concentrations 90 min after tourniquet release in the sevoflurane group from 34.6 ± 24.4 ng/mL to 47.9 ± 29.8 ng/mL (Wilcoxon test, p < 0.01) that was not observed in patients randomized to the propofol group. The two-way ANOVA showed no intergroup differences in heparan sulfate and thrombomodulin levels.. Superficial endothelial damage without alterations in the cell layer integrity was observed after tourniquet knee-ligament surgery. There was no elevation in serum endothelial biomarkers in the propofol group patients. Sevoflurane did not show the protective effect observed in in vitro and in vivo studies.. The trial was registered in www.clinicaltrials.gov (ref: NCT03772054, Registered 11 December 2018).

Topics: Adult; Endothelium; Glycocalyx; Heparitin Sulfate; Humans; Knee; Ligaments; Pilot Projects; Propofol; Reperfusion Injury; Sevoflurane; Syndecan-1; Tourniquets

Ischaemia/reperfusion-injury degrades endothelial glycocalyx. Graft glycocalyx degradation was studied in human liver transplantation.. To assess changes within the graft, blood was drawn from portal and hepatic veins in addition to systemic samples in 10 patients. Plasma syndecan-1, heparan sulfate and chondroitin sulfate, were measured with enzyme-linked immunosorbent assay.. During reperfusion, syndecan-1 levels were higher in graft caval effluent [3118 (934-6141) ng/ml, P = 0.005] than in portal venous blood [101 (75-121) ng/ml], indicating syndecan-1 release from the graft. Concomitantly, heparan sulfate levels were lower in graft caval effluent [96 (32-129) ng/ml, P = 0.037] than in portal venous blood [112 (98-128) ng/ml], indicating heparan sulfate uptake within the graft. Chondroitin sulfate levels were equal in portal and hepatic venous blood. After reperfusion arterial syndecan-1 levels increased 17-fold (P < 0.001) and heparan sulfate decreased to a third (P < 0.001) towards the end of surgery.. Syndecan-1 washout from the liver indicates extensive glycocalyx degradation within the graft during reperfusion. Surprisingly, heparan sulfate was taken up by the graft during reperfusion. Corroborating previous experimental reports, this suggests that endogenous heparan sulfate might be utilized within the graft in the repair of damaged glycocalyx.

Topics: Adult; Aged; Glycocalyx; Heparitin Sulfate; Humans; Liver; Liver Transplantation; Middle Aged; Reperfusion Injury; Syndecan-1

Heparan sulfate (HS) is a sulfated glycosaminoglycan abundant on the cell surface and in the extracellular matrix and has several biological activities including anticoagulation and anti-inflammation. Liver ischemia reperfusion injury is associated with coagulation and inflammatory responses. Here, we synthesized HS oligosaccharides with defined sulfation patterns and show that synthetic anticoagulant HS oligosaccharides limit liver ischemia reperfusion injury in a mouse model. Using a small targeted HS library, we demonstrate that an oligosaccharide that possesses both anticoagulant activity and binding affinity to HMGB1, the inflammatory target, decreases injury greater than oligosaccharides that only bind to HMGB1 or only have anticoagulant activity. HS oligosaccharides may represent a potential new therapeutic option for decreasing liver damage resulting from ischemia reperfusion injury.

Topics: Animals; Anticoagulants; Blood Coagulation; Extracellular Matrix; Heparitin Sulfate; HMGB1 Protein; Liver; Liver Diseases; Male; Mice; Mice, Inbred C57BL; Oligosaccharides; Reperfusion Injury

Ischemia-reperfusion (I/R) injury is a major clinical problem linked to vascular surgery. Currently, no drugs to prevent or to treat I/R injury are approved for clinical use. C1 inhibitor (C1 INH) is known to reduce activation of the plasma cascade systems that are involved in the pathophysiologic process of I/R injury. The aim of this study was therefore to investigate the effect of C1 INH on complement deposition and endothelial cell activation in a rat model of hind limb I/R injury.. Male Wistar rats (wild type, bred at the central animal facility, University of Bern), weighing 250 to 320 g, were used. The rats underwent 2-hour ischemia and 24-hour reperfusion by unilateral clamping of the femoral artery and additional use of a tourniquet. Five groups were divided according to intravenous treatment 5 minutes before ischemia: 50 IU/kg C1 INH (n = 5); 100 IU/kg C1 INH (n = 7); vehicle control (n = 5); nontreated control (n = 7); and normal, healthy control without intervention (n = 4). At the end, muscle edema, tissue viability, and histologic features were assessed. Deposition of immunoglobulin M, C1r, C4d, and fibrin and expression of plasminogen activator inhibitor 1, heparan sulfate (HS), E-selectin, and vascular cell adhesion molecule 1 were evaluated by fluorescence staining. In addition, high-mobility group box 1 protein was measured in plasma.. Edema formation was reduced by C1 INH at two dosages, mirrored by improved histologic injury scores and preserved muscle viability. Deposition of immunoglobulin M, C4d, and fibrin was significantly decreased by 100 IU/kg C1 INH compared with nontreated controls. Pretreatment with 100 IU/kg C1 INH also significantly reduced HS shedding and expression of plasminogen activator inhibitor 1 as well as plasma levels of high-mobility group box 1 protein.. Pretreatment with both 50 and 100 IU/kg C1 INH attenuated reperfusion injury of rat hind limbs. Pretreatment with 100 IU/kg also preserved the endothelial HS layer as well as the natural, profibrinolytic phenotype of the endothelium. Prevention of endothelial cell activation by C1 INH may therefore be a promising strategy to prevent I/R injury in the clinical setting of peripheral vascular diseases and elective surgery on extremities.

Topics: Animals; Complement Activation; Complement C1 Inhibitor Protein; Complement C1r; Complement C4b; Complement Inactivating Agents; Disease Models, Animal; E-Selectin; Edema; Endothelial Cells; Fibrin; Heparitin Sulfate; Hindlimb; HMGB1 Protein; Immunoglobulin M; Male; Muscle, Skeletal; Peptide Fragments; Plasminogen Activator Inhibitor 1; Rats, Wistar; Reperfusion Injury; Tissue Survival; Vascular Cell Adhesion Molecule-1

Ischaemia-reperfusion injury (IRI) is a main cause of morbidity after pulmonary resection surgery. The degradation of glycocalyx, a dynamic layer of macromolecules at the luminal surface of the endothelium, seems to participate in tissue dysfunction after IRI. Lidocaine has a proven anti-inflammatory activity in several tissues but its modulation of glycocalyx has not been investigated. This work aimed to investigate the potential involvement of glycocalyx in lung IRI in a lung auto-transplantation model and the possible effect of lidocaine in modulating IRI.. Three groups (sham-operated, control, and lidocaine), each consisting of 6 Large White pigs, were subjected to lung auto-transplantation. All groups received the same anaesthesia. In addition, the lidocaine group received a continuous IV administration of lidocaine (1.5 mg/kg/h). Lung tissue and plasma samples were taken before pulmonary artery clamp, before reperfusion, and 30 and 60 min post-reperfusion in order to analyse pulmonary oedema, glycocalyx components, adhesion molecules, and myeloperoxidase level.. Ischaemia caused pulmonary oedema, which was greater after reperfusion. This effect was accompanied by decreased levels of syndecan-1 and heparan sulphate in the lung samples, together with increased levels of both glycocalyx components in the plasma samples. After reperfusion, neutrophil activation and the expression of adhesion molecules were increased. All these alterations were significantly lower or absent in the lidocaine group.. Lung IRI caused glycocalyx degradation that contributed to neutrophil activation and adhesion. The administration of lidocaine was able to protect the lung from glycocalyx degradation.

Topics: Animals; Cell Adhesion; Glycocalyx; Heparitin Sulfate; Lidocaine; Lung Transplantation; Male; Neutrophil Activation; Reperfusion Injury; Swine

Vascular leakage after ischemia-reperfusion (IR) is largely attributed to the destruction of the endothelial barrier and its associated negatively charged glycocalyx. In vitro, sevoflurane attenuates these changes. Therefore, we compared sevoflurane with propofol with regard to the protection of the glycocalyx and the release of negatively charged substances in vivo.. After surgical preparation under midazolam-fentanyl, nine pigs each received either propofol or sevoflurane. Ischemia of 90 min was induced by a balloon catheter in the thoracic aorta. After 120 min of reperfusion, the anesthetics were changed back to midazolam-fentanyl. Five animals, each without aortic occlusion, served as time controls. Blood electrolyte parameters were measured, from which the strong ion gap (SIG) was calculated. Serum heparan sulfate concentrations and immunohistology served as a marker of glycocalyx destruction.. Immediately after reperfusion, SIG increased significantly only in the propofol group (+6.7 mEq/l versus baseline; p < .05), remaining stable in sevoflurane and both time-controlled groups. Initially, heparan sulfate concentration increased comparably in both experimental groups, but after 120 min, it became stable in sevoflurane-anesthetized animals, while increasing further in the propofol group (p < .05).. Unmeasured anions, predictive of negative outcome in previous studies, did not increase significantly in sevoflurane-anesthetized animals. Additionally, there was less heparan sulfate shedding over time, signaling less destruction of the glycocalyx. Therefore, in this in-vivo situation, sevoflurane proves to be superior to propofol in protecting the endothelium from IR injury.

Topics: Acid-Base Equilibrium; Anesthetics; Animals; Capillary Permeability; Disease Models, Animal; Endothelium, Vascular; Female; Glycocalyx; Heparitin Sulfate; Male; Methyl Ethers; Propofol; Reperfusion Injury; Sevoflurane; Sus scrofa

Adhesion of polymorphonuclear neutrophils and platelets to the vessel wall contributes to generating ischemia-reperfusion injury. Endothelial adhesion molecules are harbored within the glycocalyx, which covers every healthy vascular endothelium but is deteriorated by ischemia-reperfusion. Pretreating the heart with volatile anesthetics reduces myocardial infarct size and protects against ischemia-reperfusion injury. The authors analyzed a possible protective effect of sevoflurane on the glycocalyx and implications for postischemic cell adhesion.. Isolated guinea pig hearts were perfused with crystalloid buffer and subjected to 20 min of global warm ischemia and 10 min of reperfusion. An intracoronary bolus of 3 x 10(6) polymorphonuclear neutrophilic leukocytes or 1 x 10(9) platelets of human origin was applied after reperfusion, either with or without pretreating with 0.5 or 1 minimal alveolar concentration sevoflurane. The number of sequestered cells was calculated from the difference between coronary input and output. Coronary effluent was collected throughout reperfusion to measure shedding of the glycocalyx.. Ischemia-reperfusion induced a significant increase in median (interquartile range) adhesion versus control nonischemic hearts of both leukocytes (38.9 (36.3-42.9) vs. 14.5 (13.1-16.0)%) and platelets (25.0 (22.5-27.1) vs. 9.4 (8.4-10.7)%). Shedding was evidenced by eightfold increases in washout of syndecan-1 and heparan sulfate versus basal. Sevoflurane reduced cell adhesion to near basal at 1 minimal alveolar concentration (leukocytes: 21.2% (19.2-23.9%), platelets: 11.5% (10.4-12.0%). Shedding measurements and electron microscopy demonstrated that sevoflurane-treated hearts retained much of their 200 nm-thick glycocalyx.. Sevoflurane reduces glycocalyx shedding in the postischemic coronary bed, maintaining the natural cover for endothelial adhesion molecules and, thus, reducing cell adhesion. This may explain beneficial outcomes linked to clinical use of volatile anesthetics after ischemia-reperfusion.

Topics: Anesthetics, Inhalation; Animals; Cell Adhesion; Coronary Circulation; Edema; Endothelium; Flow Cytometry; Glycocalyx; Guinea Pigs; Heparitin Sulfate; Humans; In Vitro Techniques; Methyl Ethers; Microscopy, Electron; Neutrophils; Platelet Adhesiveness; Reperfusion Injury; Sevoflurane; Syndecan-1

Increased understanding of the pathophysiology of ischemic acute kidney injury in renal transplantation may lead to novel therapies that improve early graft function. Therefore, we studied the renal microcirculation in ischemically injured kidneys from donors after cardiac death (DCD) and in living donor kidneys with minimal ischemia. During transplant surgery, peritubular capillaries were visualized by sidestream darkfield imaging. Despite a profound reduction in creatinine clearance, total renovascular resistance of DCD kidneys was similar to that of living donor kidneys. In contrast, renal microvascular perfusion in the early reperfusion period was 42% lower in DCD kidneys compared with living donor kidneys, which was accounted for by smaller blood vessel diameters in DCD kidneys. Furthermore, DCD kidneys were characterized by smaller red blood cell exclusion zones in peritubular capillaries and by greater production of syndecan-1 and heparan sulfate (main constituents of the endothelial glycocalyx) compared with living donor kidneys, providing strong evidence for glycocalyx degradation in these kidneys. We conclude that renal ischemia and reperfusion is associated with reduced capillary blood flow and loss of glycocalyx integrity. These findings form the basis for development of novel interventions to prevent ischemic acute kidney injury.

Topics: Acute Kidney Injury; Adolescent; Adult; Capillaries; Endothelium, Vascular; Female; Glycocalyx; Heparitin Sulfate; Humans; Ischemia; Kidney Function Tests; Kidney Transplantation; Living Donors; Male; Middle Aged; P-Selectin; Renal Circulation; Reperfusion Injury; Syndecan-1; Young Adult

This study was undertaken to examine the mechanism by which danaparoid sodium (DS), a heparinoid that contains mainly heparan sulfate, prevents reperfusion-induced hepatic damage in a rat model of ischemia/reperfusion (I/R)-induced liver injury. Administration of DS significantly reduced liver injury and inhibited the decrease in hepatic tissue blood flow in rats. DS attenuated hepatic I/R-induced increases in hepatic tissue levels of tumor necrosis factor (TNF) and myeloperoxidase (MPO) in vivo. In contrast, neither monocytic TNF production nor neutrophil activation was inhibited by DS in vitro. DS enhanced I/R-induced increases in levels of calcitonin-gene related peptide (CGRP), a neuropeptide released from sensory neurons, and of 6-ketoprostaglandin (PG) F (1a) , a stable metabolite of PGI (2) , in liver tissues. The therapeutic effects of DS were not seen in animals pretreated with capsazepine, an inhibitor of sensory neuron activation. The distribution of heparan sulfate in the perivascular area was significantly increased by DS administration in this rat model. DS significantly increased CGRP release from isolated rat dorsal root ganglion neurons (DRG) in vitro, while DX-9065a, a selective inhibitor of activated factor X, did not. DS enhanced anandamide-induced CGRP release from DRG in vitro. These observations strongly suggested that DS might reduce I/R-induced liver injury in rats by attenuating inflammatory responses. These therapeutic effects of DS might be at least partly explained by its enhancement of sensory neuron activation, leading to the increase the endothelial production of PGI (2) .

Topics: Animals; Calcitonin Gene-Related Peptide; Chondroitin Sulfates; Dermatan Sulfate; Epoprostenol; Ganglia, Spinal; Heparitin Sulfate; Inflammation; Liver; Male; Neurons, Afferent; Rats; Rats, Wistar; Regional Blood Flow; Reperfusion Injury

Factor H-associated hemolytic uremic syndrome (HUS) is a genetic form of thrombotic microangiopathy characterized by deficient factor H (HF-1) levels/activity and uncontrolled complement activation. The disorder mostly leads to end-stage renal disease and often recurs after kidney transplantation. We previously demonstrated that in a child with HF-1-associated HUS a simultaneous kidney and liver transplantation restored the defective HF-1 with no recurrence of the disease in the transplanted kidney. Here we describe a second childhood case of HF-1-associated HUS treated by combined kidney and liver transplant and complicated by a fatal, primary non-function of the liver graft. Graft hypoperfusion during surgery triggered ischemia/reperfusion changes and complement activation. Conceivably, as a result of defective complement regulatory potential, massive shedding of vascular heparan sulfates was documented in the transplanted liver. This might have impaired the physiological thromboresistance of vascular endothelium ending with widespread microvascular thrombosis and infarction. This case indicates that more fundamental research is needed before combined liver and kidney transplant is considered an option for children with HF-1-associated HUS.

Topics: Complement Activation; Complement Factor H; Endothelium, Vascular; Exons; Fatal Outcome; Female; Graft Rejection; Hemolytic-Uremic Syndrome; Heparitin Sulfate; Humans; Infant; Kidney Transplantation; Liver; Liver Failure; Liver Transplantation; Mutation, Missense; Perfusion; Reperfusion Injury

Heparin has long been established as an anticoagulant. Although heparin has been demonstrated to reduce brain injury after ischemia and reperfusion, its mechanism of action remains unknown. Recent investigations reveal that it can modulate biological processes such as binding to adhesion receptors on endothelial cells and leukocytes. The authors hypothesized that heparin's protective effect is closely related to its antileukocyte adherence property. They evaluated the efficacy of sulfated polysaccharides (unfractionated heparin, low-molecular-weight heparin, heparan sulfate, chondroitin sulfate C, and dextran sulfate) on leukocyte accumulation, infarction size, and neurological outcome after transient focal cerebral ischemia in rats subjected to 1 hour of ischemia and 48 hours of reperfusion. Forty-nine animals were included in the study. The animals receiving unfractionated heparin or dextran sulfate showed a significant reduction in leukocyte accumulation, infarct size, and neurological dysfunction 48 hours after reperfusion (p < 0.05) when compared to untreated animals. The animals receiving unfractionated heparin also showed significantly better results than the animals receiving an equivalent anticoagulant dose of low-molecular-weight heparin. These data indicate that heparin's antileukocyte property plays a more important role than its anticoagulant ability in neuronal protection. The relative potency of the sulfated polysaccharides tested in leukocyte depletion was closely related to their degree of sulfation. Thus, in addition to demonstrating the potential efficacy of heparin as a therapeutic agent for ischemia and reperfusion injury by the prevention of leukocyte accumulation, the results also serve as a basis for studying important cellular and molecular events that contribute to tissue damage.

Topics: Animals; Cell Adhesion; Chondroitin Sulfates; Dextran Sulfate; Heparin; Heparitin Sulfate; Ischemic Attack, Transient; Leukocytes; Male; Peroxidase; Rats; Rats, Sprague-Dawley; Reperfusion Injury

The aim of the study presented here was to investigate whether, in patients showing immediate graft function after renal transplantation, cold-ischemia and reperfusion lead to damage of the glomerular basement membrane and consequently to a loss of heparan sulfate proteoglycans. Loss of these heparan sulfate proteoglycans is a major cause of proteinuria. Time-dependent changes in urinary excretion rates of heparan sulfate proteoglycans but also of total protein, albumin, low- and high-molecular-weight proteins were analyzed quantitatively and by polyacrylamid-gel-electrophoresis in eight patients. Immediately after renal transplantation, severe proteinuria with an excretion rate of up to 251 +/- 108 mg/min was apparent and rapidly declined within 24 h to 4.11 +/- 2.80 mg/min. The gel-electrophoretic pattern showed a nonselective glomerular and tubular proteinuria. The excretion rate of heparan sulfate proteoglycan was increased in this initial reperfusion phase (up to 7 h), most probably because of ischemia- and reperfusion-induced damage of the glomerular basement membrane. The initial nonselective glomerular proteinuria disappeared within 48 h, changing to a mild selective glomerular proteinuria. In this second phase (7 to 48 h), lower levels of heparan sulfate proteoglycan excretion were observed (0.54 +/- 0.54 microgram/min versus 1.66 +/- 1.93 micrograms/min, P < 0.05). However, during the repair process of the glomerular basement membrane, heparan sulfate proteoglycan is synthesized de novo, leading to an increasing heparan sulfate proteoglycan content of the glomerular basement membrane. This second phase is paralleled by the change from a nonselective to a selective glomerular proteinuria. In the third phase, when the heparan sulfate proteoglycan content of the glomerular basement membrane normalizes, glomerular proteinuria was abolished in most of the patients.

Topics: Adult; Basement Membrane; Female; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Humans; Immunohistochemistry; Kidney; Kidney Glomerulus; Kidney Transplantation; Male; Middle Aged; Proteinuria; Proteoglycans; Reperfusion Injury

Although standard heparin has been demonstrated to reduce endothelial cell dysfunction in acute ischemia-reperfusion injury, its mechanism of action remains unknown. We hypothesized that heparin's salutary endothelial effects are independent of its conventional anticoagulant activity and are not caused by nonspecific polyanion effects.. Isolated rat hindlimbs were perfused at constant pressure with an albumin-enriched crystalloid buffer. After 60 minutes of normothermic ischemia, endothelial function was assessed by measurement of endothelial-dependent vasodilation by log increment infusion of acetylcholine. Endothelial-independent vasodilation was measured by exposure to nitroprusside. Some groups were pretreated with heparinoids possessing minimal or intermediate anticoagulant activity.. Treatment with heparinoids with low anticoagulant activity significantly increased endothelial-dependent vasodilation when compared with the nontreated ischemic group and were statistically indistinguishable from the nonischemic control. Treatment with dextran sulfate, a randomly sulfated polymer with size and charge characteristics similar to heparin, did not change postischemic vasodilation. Endothelial-independent vasodilation was largely unaffected by ischemia-reperfusion or drug treatment.. A heparinoid with negligible antithrombin-binding activity (Astenose) attenuated postischemic endothelial dysfunction, suggesting that its mechanism of action was independent of anticoagulant activity. Failure of dextran sulfate to be protective implied that the effect was not caused by nonspecific polyanion action.

Topics: Acute Disease; Animals; Anticoagulants; Chondroitin Sulfates; Dermatan Sulfate; Dextran Sulfate; Endothelium, Vascular; Heparin; Heparitin Sulfate; Hindlimb; In Vitro Techniques; Ischemia; Male; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Vasodilation