losartan-potassium and Subarachnoid-Hemorrhage

Subarachnoid haemorrhage (SAH) caused by a ruptured aneurysm accounts for only 5 % of strokes, but occurs at a fairly young age and carries a poor prognosis. Delayed cerebral ischaemia (DCI) is an important cause of death and dependence after aneurysmal SAH. The current mainstay of preventing DCI is nimodipine and maintenance of normovolemia, but even with this strategy DCI occurs in a considerable proportion of patients.Several drugs have been developed that have the potential to limit cerebral vasospasm and delayed ischaemic neurologic deficit, thus improving outcome for patients. However, although numerous agents can prevent arterial narrowing and/or block the excitatory cascade of events leading to ischaemic neuronal death in experimental conditions, there is still no pharmacologic agent that has been shown conclusively to improve the outcome in clinical practice.Erythropoietin (EPO) is a well-known erythropoietic hormone recently found to exert neuroprotective properties and has been shown to reduce cerebral vasospasm and infarct volume after experimental SAH. In humans, although EPO treatment did not impact the overall incidence of vasospasm, it significantly reduced the incidence of severe vasospasm, the incidence of delayed ischaemic deficits with new cerebral infarcts, and the duration of impaired autoregulation. The current study provides new evidence for the potential benefit and relative safety of EPO for the treatment of SAH in humans. Future clinical trials will hopefully provide definite evidence whether EPO treatment is beneficial in SAH patients.

Topics: Animals; Brain Ischemia; Erythropoietin; Humans; Stroke; Subarachnoid Hemorrhage; Vasospasm, Intracranial

Anemia is common in patients with aneurysmal subarachnoid hemorrhage (SAH), but these patients have constituted only a small fraction of those studied in large trials of anemia and transfusion. Unlike other critically ill patients, those with SAH face a well-defined risk of vasospasm and cerebral ischemia in the weeks after their hemorrhage. The risk of ongoing ischemia may make them less able to tolerate anemia and more likely to benefit from blood transfusion. The available data show that anemia is associated with poor outcomes after SAH but that blood transfusion does not consistently improve physiological markers, and it may be associated with poor outcomes. Most of these data are observational in nature, although 1 recent study demonstrated the safety and feasibility of maintaining relatively high transfusion thresholds in patients with SAH. Larger, randomized trials are needed to determine at what levels of anemia patients with SAH might benefit from transfusion, the optimal timing of transfusion, and how to identify those patients who are most likely to benefit.

Topics: Anemia; Blood Transfusion; Erythrocyte Aging; Erythropoietin; Hemodilution; Humans; Intraoperative Care; Oxygen Consumption; Preoperative Care; Recombinant Proteins; Subarachnoid Hemorrhage; Vasospasm, Intracranial

Topics: Acute Lung Injury; Adult; Anemia; Blood Preservation; Blood Specimen Collection; Brain Injuries; Critical Illness; Erythrocyte Transfusion; Erythropoietin; Hemorrhage; Humans; Myocardial Ischemia; Nervous System Diseases; Sepsis; Shock; Stroke; Subarachnoid Hemorrhage

Topics: Aneurysm, Ruptured; Epoetin Alfa; Erythropoietin; Humans; Neuroprotective Agents; Recombinant Proteins; Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) has a worldwide incidence of approximately 10.5 cases per 100,000 person-years and constitutes 3% of all strokes. Erythropoietin (EPO) has recently been proposed for the treatment of a variety of brain diseases, including SAH, because of its neuroprotective effects. Hence, the current evidence in the published literature was reviewed to determine the potential utility of EPO in the treatment of SAH.. A careful retrospective review of the literature was performed to determine the potential benefit of employing EPO in the treatment of SAH and its sequelae.. Careful literature review revelaed that the use of EPO may not necessarily reduce the incidence of vasospasm after SAH, but it may reduce the severity and its eventual outcome.. Given the recent trial results, a dose-escalation study and subsequent randomized trial should be considered.

Topics: Erythropoietin; Humans; Neuroprotective Agents; Recombinant Proteins; Retrospective Studies; Stroke; Subarachnoid Hemorrhage; Treatment Outcome; Vasospasm, Intracranial

Cerebral vasospasm and the resulting cerebral ischemia occurring after subarachnoid hemorrhage (SAH) are still responsible for the considerable morbidity and mortality in patients affected by cerebral aneurysms. Mechanisms contributing to the development of vasospasm, abnormal reactivity of cerebral arteries and cerebral ischemia after SAH have been intensively investigated in recent years. It has been suggested that the pathogenesis of vasospasm is related to a number of pathological processes, including endothelial damage, smooth muscle cell contraction resulting from spasmogenic substances generated during lyses of subarachnoid blood clots, changes in vascular responsiveness and inflammatory or immunological reactions of the vascular wall. A great deal of experimental and clinical research has been conducted in an effort to find ways to prevent these complications. However, to date, the main therapeutic interventions remain elusive and are limited to the manipulation of systemic blood pressure, alteration of blood volume or viscosity, and control of arterial dioxide tension. Even though no single pharmacological agent or treatment protocol has been identified which could prevent or reverse these deadly complications, a number of promising drugs have been investigated. Among these is the hormone erythropoietin (EPO), the main regulator of erythropoiesis. It has recently been found that EPO produces a neuroprotective action during experimental SAH when its recombinant form (rHuEPO) is systemically administered. This topic review collects the relevant literature on the main investigative therapies for cerebrovascular dysfunction after aneurysmal SAH. In addition, it points out rHuEPO, which may hold promise in future clinical trials to prevent the occurrence of vasospasm and cerebral ischemia after SAH.

Topics: Animals; Cerebrovascular Disorders; Endothelins; Erythropoietin; Humans; Nitric Oxide Donors; Potassium Channels; Recombinant Proteins; Subarachnoid Hemorrhage

Erythropoietin (EPO) was proven as a promising approach for experimental subarachnoid hemorrhage (SAH). Clinical data are, however, inconclusive so far. A detailed characterization of specific EPO effects could facilitate the design of trials. The aim of the present investigation was, therefore, to characterize these effects on prevention of delayed proximal cerebral vasospasm (CVS), impaired microcirculation and cerebral blood flow (CBF) after experimental SAH.. 27 male Sprague-Dawley rats were randomized in 3 groups: Sham, SAH control, and SAH EPO. SAH was induced by injection of 0.2ml autologous blood into the cisterna magna on days 1 and 2. Animals of the SAH EPO group received 5000iU rh EPO α 6h after the 2nd SAH intravenously. Surviving animals were examined on day 5 by MR perfusion weighted imaging (PWI). Cerebral blood flow (CBF) and volume (CBV) were determined by PWI, proximal CVS by basilar artery (BA) diameter, and neuroprotection by hippocampal cell count (CA1-CA4).. BA diameter was significantly reduced in both SAH groups, but improved significantly after EPO (Sham: 144±3μm, SAH control: 79±6μm, SAH EPO 109±4μm). The rrCBV ratio was 8.78±0.72 Sham, 5.14±1.73 SAH control, and 6.80±0.44 SAH EPO. The improvement by EPO did not reach statistical significance. RrCBF ratio was also significantly reduced in both SAH groups, but was significantly improved by EPO (Sham: 8.78±0.34, SAH control: 4.26±1.05, SAH EPO 5.85±0.46). Surviving neuronal cells were significantly reduced in SAH controls in all areas, but in SAH EPO only in CA1.. The present data suggest that an EPO application in a timely distance to the SAH is sufficient to prevent delayed proximal CVS, but that the doses were insufficient to improve microcirculation or to be directly neuroprotective.

Topics: Analysis of Variance; Animals; Basilar Artery; Brain; Cell Count; Cerebrovascular Circulation; Disease Models, Animal; Dose-Response Relationship, Drug; Erythropoietin; Hemodynamics; Magnetic Resonance Imaging; Male; Neurologic Examination; Rats; Rats, Sprague-Dawley; Subarachnoid Hemorrhage; Time Factors; Vasospasm, Intracranial

Vasospasm-related delayed cerebral ischemia (DCI) significantly impacts on outcome after aneurysmal subarachnoid hemorrhage (SAH). Erythropoietin (EPO) may reduce the severity of cerebral vasospasm and improve outcome, however, underlying mechanisms are incompletely understood. In this study, the authors aimed to investigate the effect of EPO on cerebral metabolism and brain tissue oxygen tension (PbtO2).. Seven consecutive poor grade SAH patients with multimodal neuromonitoring (MM) received systemic EPO therapy (30.000 IU per day for 3 consecutive days) for severe cerebral vasospasm. Cerebral perfusion pressure (CPP), mean arterial blood pressure (MAP), intracranial pressure (ICP), PbtO2 and brain metabolic changes were analyzed during the next 24 hours after each dose given. Statistical analysis was performed with a mixed effects model.. A total of 22 interventions were analyzed. Median age was 47 years (32-68) and 86 % were female. Three patients (38 %) developed DCI. MAP decreased 2 hours after intervention (P < 0.04) without significantly affecting CPP and ICP. PbtO2 significantly increased over time (P < 0.05) to a maximum of 7 ± 4 mmHg increase 16 hours after infusion. Brain metabolic parameters did not change over time.. EPO increases PbtO2 in poor grade SAH patients with severe cerebral vasospasm. The effect on outcome needs further investigation.

Topics: Adult; Aged; Brain; Dose-Response Relationship, Drug; Erythropoietin; Female; Humans; Male; Middle Aged; Oxygen; Oxygen Consumption; Subarachnoid Hemorrhage; Treatment Outcome; Vasospasm, Intracranial

Delayed ischemic deficits (DIDs), a major source of disability following aneurysmal subarachnoid hemorrhage (aSAH), are usually associated with severe cerebral vasospasm and impaired autoregulation. Systemic erythropoietin (EPO) therapy has been demonstrated to have neuroprotective properties acting via EPO receptors on cerebrovascular endothelia and ischemic neurons. In this trial, the authors explored the potential neuroprotective effects of acute EPO therapy following aSAH.. Within 72 hours of aSAH, 80 patients (age range 24-82 years) were randomized to receive intravenous EPO (30,000 U) or placebo every 48 hours for a total of 90,000 U. Primary end points were the incidence, duration, and severity of vasospasm and impaired autoregulation on transcranial Doppler ultrasonography. Secondary end points were incidence of DIDs and outcome at discharge and at 6 months.. Randomization characteristics were balanced except for age, with the EPO group being older (mean age 59.6 vs 53.3 years, p=0.034). No differences were demonstrated in the incidence of vasospasm and adverse events; however, patients receiving EPO had a decreased incidence of severe vasospasm from 27.5 to 7.5% (p=0.037), reduced DIDs with new cerebral infarcts from 40.0 to 7.5% (p=0.001), a shortened duration of impaired autoregulation (ipsilateral side, p<0.001), and more favorable outcome at discharge (favorable Glasgow Outcome Scale score, p=0.039). Among the 71 survivors, the EPO group had fewer deficits measured with National Institutes of Health Stroke Scale (median Score 2 vs 6, p=0.008).. This preliminary study showed that EPO seemed to reduce delayed cerebral ischemia following aSAH via decreasing severity of vasospasm and shortening impaired autoregulation.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Blood Pressure; Blood Transfusion; Brain Ischemia; Double-Blind Method; Erythropoietin; Female; Follow-Up Studies; Homeostasis; Humans; Male; Middle Aged; Neuroprotective Agents; Placebos; Subarachnoid Hemorrhage; Treatment Outcome; Ultrasonography, Doppler, Transcranial; Vasospasm, Intracranial; Young Adult

Erythropoietin (EPO) is neuroprotective in experimental models of stroke and subarachnoid haemorrhage (SAH) and possibly in patients with thromboembolic stroke. We studied the efficacy and safety of EPO in patients with SAH.. A larger scale clinical trial was planned but preliminarily terminated because of a lower than expected inclusion rate. However, 73 patients were randomised to treatment with EPO (500 IU/kg/day for three days) or placebo. The primary endpoint was Glasgow Outcome Score at six months. We further studied surrogate measures of secondary ischaemia, i.e. transcranial Doppler (TCD) flow velocity, symptomatic vasospasm, cerebral metabolism (microdialysis) and jugular venous oximetry, biochemical markers of brain damage (S-100beta and neuron specific enolase) and blood-brain barrier integrity.. The limited sample size precluded our primary hypotheses being verified and refuted. However, data from this study are important for any other study of SAH and as much raw data as possible are presented and can be included in future meta analyses. On admission the proportion of patients in a poor condition was higher in the EPO group compared with the placebo group but the difference was statistically insignificant. In the EPO-treated patients the CSF concentration of EPO increased 600-fold. Except for a higher extracelullar concentration of glycerol in the EPO group probably caused by the poorer clinical condition of these patients, there were no statistically significant group differences in the primary or secondary outcome measures. EPO was well tolerated.. Beneficial effects of EPO in patients with SAH cannot be excluded or concluded on the basis of this study and larger scale trials are warranted.

Topics: Adult; Aged; Blood Flow Velocity; Brain; Brain Damage, Chronic; Double-Blind Method; Epoetin Alfa; Erythropoietin; Female; Follow-Up Studies; Glasgow Outcome Scale; Hematinics; Hospital Mortality; Humans; Intracranial Aneurysm; Magnetic Resonance Imaging; Male; Microdialysis; Microsurgery; Middle Aged; Neuroprotective Agents; Oxygen Consumption; Premedication; Recombinant Proteins; Subarachnoid Hemorrhage; Tomography, X-Ray Computed; Ultrasonography, Doppler, Transcranial

Inflammatory modulation mediated by microglial M1/M2 polarization is one of the main pathophysiological processes involved in early brain injury (EBI) after subarachnoid haemorrhage (SAH). Previous studies have shown that recombinant human erythropoietin (rhEPO) alleviates EBI following experimental SAH. However, the mechanisms of this beneficial effect are still poorly understood. Recent research has suggested that EPO shows anti-inflammatory properties. Therefore, we tried to analyse whether rhEPO administration influenced microglial M1/M2 polarization in early brain injury after SAH and to identify the underlying molecular mechanism of any such effect. We found that treatment with rhEPO markedly ameliorated SAH-induced EBI, as shown by reductions in brain cell apoptosis, neuronal necrosis, albumin exudation and brain edema. Moreover, the expression levels of p-JAK2 and p-STAT3 were significantly increased in the cortex after SAH induction and were further increased by EPO treatment; in addition, the p-JAK2 inhibitor AZD1480 impaired the protective effect of EPO against SAH-induced EBI in vivo. Furthermore, EPO promoted the polarization of microglia towards the protective M2 phenotype and alleviated inflammation. In cultured microglia under oxyhemoglobin (OxyHb) treatment, EPO up-regulated the expression of the EPO receptor (EPOR), which did not occur in response to OxyHb treatment alone, and EPO magnified OxyHb-induced increases in p-JAK2 and p-STAT3 and modulated OxyHb-challenged microglial polarization towards M2. Interestingly, the effect of EPO on microglia polarization was cancelled by EPOR knockdown or by p-JAK2 or p-STAT3 inhibition, suggesting a core role of the EPOR/JAK2/STAT3 pathway in modulating microglial function and phenotype. In conclusion, the therapeutic effect of rhEPO on the early brain injury after SAH may relate to its modulation of inflammatory response and microglia M1/M2 polarization, which may be mediated in part by the EPOR/JAK2/STAT3 signalling pathway. These results improved the understanding of the anti-inflammatory effect of EPO on microglia polarization, which might optimize the therapeutic modalities of EPO treatment with SAH.

Topics: Animals; Anti-Inflammatory Agents; Brain Edema; Cell Differentiation; Cell Line; Cerebral Cortex; Disease Models, Animal; Erythropoietin; Gene Expression Regulation; Humans; Injections, Intraventricular; Janus Kinase 2; Mice; Mice, Inbred C57BL; Microglia; Neurons; Oxyhemoglobins; Pyrazoles; Pyrimidines; Receptors, Erythropoietin; Recombinant Proteins; Signal Transduction; STAT3 Transcription Factor; Stereotaxic Techniques; Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a common condition with relatively poor clinical outcome. Pulmonary complication after SAH is an important contributor to poor outcome. Previous studies have shown that labile zinc and inflammatory mediators participate in many pathophysiological processes. The present study investigated the effects of SAH on the levels of labile zinc and certain proinflammatory factors in rat lung and determined the effect of erythropoietin (EPO) on the pulmonary labile zinc and the inflammatory factor after SAH in rats.. Experiment 1 aimed to investigate the time course of increase of pulmonary labile zinc, wet/dry weight ratio, and the expression of inflammatory mediators after SAH. In Experiment 2, we chose the maximum time point which lung injury was maximally severity and assessed the effect of EPO on regulation of the pulmonary labile zinc, inflammatory reaction, and wet/dry weight ratio after SAH.. SAH caused a gradual increase of pulmonary labile zinc as demonstrated by fluorescence staining with Zinpyr-4. The levels of TNF-α and IL-8 and the lung wet/dry weight ratios were higher in the SAH groups compared to the control group and peaked on 3 days following SAH (p < 0.05). EPO significantly reduced the pulmonary labile zinc, the inflammatory mediators, and the lung wet/dry weight ratio compared with SAH group (p < 0.05).. EPO can protect lung from SAH-induced injury by attenuating pulmonary inflammation and labile zinc accumulation in vivo.

Topics: Animals; Disease Models, Animal; Erythropoietin; Inflammation Mediators; Lung; Lung Injury; Male; Rats; Rats, Sprague-Dawley; Subarachnoid Hemorrhage; Zinc

Topics: Brain Ischemia; Erythropoietin; Female; Humans; Male; Neuroprotective Agents; Subarachnoid Hemorrhage

Topics: Animals; Erythropoietin; Hemodynamics; Male; Subarachnoid Hemorrhage; Vasospasm, Intracranial

Darbepoetin alpha is a hypersialylated analogue of erythropoietin effective for activating erythropoietin-receptors. This study investigated the vasodilator and neuroprotective effects of darbepoetin alpha on an experimental subarachnoid hemorrhage model and compared it with erythropoietin.. Forty adult male New Zealand white rabbits were randomly divided into four groups of ten rabbits each: group 1 (control), group 2 (subarachnoid hemorrhage), group 3 (erythropoietin), and group 4 (darbepoetin alpha). Recombinant human erythropoietin was administered at a dose of 1,000 U/kg intraperitoneally after the induction of subarachnoid hemorrhage and continued every 8 h up to 72 h. Darbepoetin alpha was administered at a single intraperitoneal dose of 30 μg/kg. Animals were killed 72 h after subarachnoid hemorrhage. Basilar artery cross-sectional areas, arterial wall thicknesses, hippocampal degeneration scores and biochemical analyses were measured in all groups.. Both erythropoietin and darbepoetin alpha treatments were found to attenuate cerebral vasospasm and provide neuroprotection after subarachnoid hemorrhage in rabbits. Darbepoetin alpha revealed better morphometric and histopathological results than erythropoietin among experimental subarachnoid hemorrhage-induced vasospasm.. Our findings, for the first time, showed that darbepoetin alpha can prevent vasospasm and provides neuroprotection following experimental subarachnoid hemorrhage. Moreover, darbepoetin alpha showed better results when compared with erythropoietin.

Topics: Animals; Basilar Artery; Darbepoetin alfa; Epoetin Alfa; Erythropoietin; Hematinics; Hippocampus; Humans; Male; Neuroprotective Agents; Rabbits; Recombinant Proteins; Subarachnoid Hemorrhage; Vasoconstriction; Vasospasm, Intracranial

Hypoxia-inducible factor 1α (HIF-1α) is a master regulator of cellular adaptation to hypoxia and has been proposed as a potent therapeutic target for cerebral ischemia. However, research on the expression and effects of HIF-1α in subarachnoid hemorrhage (SAH) is limited. The aim of the present study was to investigate the expression of HIF-1α in the hippocampus and its possible protective effect against hippocampal apoptosis and cognitive dysfunction in a rat model of SAH. Seventy-two Sprague-Dawley (SD) rats were randomly divided into the sham group, the SAH+vehicle group, and the SAH+YC-1 group. Immunohistochemical staining and western blotting analyses revealed that the expression of HIF-1α and its downstream effectors, vascular endothelial growth factor (VEGF), erythropoietin (EPO), and glucose transporter 1 (GLUT1), increased in the hippocampus 48h after the induction of SAH. YC-1 blocked this upregulation. The number of active caspase-3-positive cells and the expression of active caspase-3 in the hippocampus significantly increased in the YC-1 group relative to the vehicle group. A cell death assay further revealed that DNA fragmentation was significantly increased at 48h in the YC-1 group compared with the vehicle group. In Morris water maze (MWM) tests, the YC-1 group showed increased escape latency times and distances as well as reduced time spent and distance traveled in the target quadrant. These results indicate that hippocampal apoptosis increased and cognitive function deteriorated when HIF-1α was inhibited, suggesting that HIF-1α has a neuroprotective effect in SAH and may represent an effective therapeutic target.

Topics: Animals; Apoptosis; Blood Pressure; Caspase 3; Cognition Disorders; Disease Models, Animal; DNA Fragmentation; Enzyme-Linked Immunosorbent Assay; Erythropoietin; Excitatory Amino Acid Transporter 2; Hippocampus; Hypoxia-Inducible Factor 1, alpha Subunit; Indazoles; Male; Maze Learning; Platelet Aggregation Inhibitors; Rats; Rats, Sprague-Dawley; Reaction Time; Subarachnoid Hemorrhage; Vascular Endothelial Growth Factor A

In a previous randomized controlled trial, the authors demonstrated that acute erythropoietin (EPO) therapy reduced severe vasospasm and delayed ischemic deficits (DIDs) following aneurysmal subarachnoid hemorrhage. In this study, the authors aimed to investigate the potential interaction of neurovascular protection by EPO with age, sepsis, and concurrent statin therapy.. The clinical events of 80 adults older than 18 years and with < 72 hours of aneurysmal subarachnoid hemorrhage, who were randomized to receive 30,000 U of intravenous EPO-beta or placebo every 48 hours for a total of 3 doses, were analyzed by stratification according to age (< or > or = 60 years), sepsis, or concomitant statin therapy. End points in the trial included cerebral vasospasm and impaired autoregulation on transcranial Doppler ultrasonography, DIDs, and unfavorable outcome at discharge and at 6 months measured with the modified Rankin Scale and Glasgow Outcome Scale. Analyses were performed using the t-test and/or ANOVA for repeated measurements.. Younger patients (< 60 years old) or those without sepsis obtained benefits from EPO by a reduction in vasospasm, impaired autoregulation, and unfavorable outcome at discharge. Compared with nonseptic patients taking EPO, those with sepsis taking EPO had a lower absolute reticulocyte count (nonsepsis vs sepsis, 143.5 vs. 105.8 x 10(9)/L on Day 6; p = 0.01), suggesting sepsis impaired both hematopoiesis and neurovascular protection by EPO. In the EPO group, none of the statin users suffered DIDs (p = 0.078), implying statins may potentiate neuroprotection by EPO.. Erythropoietin-related neurovascular protection appears to be attenuated by old age and sepsis and enhanced by statins, an important finding for designing Phase III trials.

Topics: Age Factors; Aneurysm, Ruptured; Clinical Trials, Phase II as Topic; Double-Blind Method; Drug Synergism; Drug Therapy, Combination; Erythropoietin; Glasgow Outcome Scale; Hematopoiesis; Homeostasis; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperemia; Intracranial Aneurysm; Middle Aged; Neuroprotective Agents; Randomized Controlled Trials as Topic; Recombinant Proteins; Sepsis; Subarachnoid Hemorrhage; Ultrasonography, Doppler, Transcranial; Vasospasm, Intracranial

Topics: Animals; Brain Ischemia; Clinical Trials, Phase II as Topic; Disease Models, Animal; Erythropoietin; Humans; Neuroprotective Agents; Randomized Controlled Trials as Topic; Recombinant Proteins; Subarachnoid Hemorrhage; Time Factors

Recombinant human erythropoietin (rhEPO) has demonstrated beneficial effects against vasospasm and brain damage at the late stage of subarachnoid hemorrhage (SAH); however few investigations have been done about the effect of rhEPO on SAH-induced early brain injury (EBI) and also the underlying mechanisms remain unclear. This study was undertaken to evaluate the influence of rhEPO on the nuclear factor erythroid 2-related factor 2 and antioxidant responsive element (Nrf2-ARE) pathway and early brain injury in rats after SAH. Adult male SD rats were divided into four groups: (1) control group (n=18); (2) SAH group (n=18); (3) SAH+vehicle group (n=18); and (4) SAH+rhEPO group (n=18). The rat SAH model was induced by injection of 0.3 ml fresh arterial, non-heparinized blood into the prechiasmatic cistern in 20s. In SAH+rhEPO group, rhEPO was administered i.p. at 1000U/kg starting 5 min after the induction of SAH and repeated every 8h for 48 h. Brain samples were extracted at 48 h after SAH. As a result, we found that treatment with rhEPO markedly increased expressions of Nrf2-ARE pathway related agents, such as Nrf2, heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase-1 (NQO1), and glutathione S-transferase α-1 (GST-α1). Administration of rhEPO following SAH significantly ameliorated EBI, such as cortical apoptosis, brain edema, and blood-brain barrier (BBB) impairment. In conclusion, post-SAH rhEPO administration may attenuate EBI in this SAH model, possibly through activating Nrf2-ARE pathway and modulating cerebral oxidative stress by inducing antioxidant and detoxifying enzymes.

Topics: Animals; Base Sequence; Blood-Brain Barrier; Blotting, Western; Brain Injuries; DNA Primers; Erythropoietin; In Situ Nick-End Labeling; Male; NF-E2-Related Factor 2; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Subarachnoid Hemorrhage

Topics: Brain Ischemia; Erythropoietin; Humans; Neurosurgical Procedures; Recombinant Proteins; Subarachnoid Hemorrhage; Vasospasm, Intracranial

Topics: Erythropoiesis; Erythropoietin; Homeostasis; Humans; Recombinant Proteins; Subarachnoid Hemorrhage; Treatment Outcome

Previous studies have shown that recombinant human erythropoietin (rhEPO) can attenuate the degree of cerebral vasospasm following experimental subarachnoid hemorrhage (SAH). However, the mechanisms for this beneficial effect are still poorly understood. SAH-induced endothelial apoptosis may trigger, aggravate, and maintain cerebral vasospasm. We, therefore, tried to analyze whether rhEPO administration influenced the endothelial cell apoptosis in the basilar artery after SAH. Another aim of the current study was to investigate the modulation of rhEPO on the activity of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), which played an important role in the signaling of apoptosis. A total of 48 rabbits were randomly divided into four groups; control group, SAH group, SAH+vehicle group, and SAH+rhEPO group. All SAH animals were subjected to injection of autologous blood into cisterna magna twice on day 0 and day 2. The rhEPO was administered i.p. starting 5 min after the induction of SAH on day 0 and repeated every 8 h for 120 h. The basilar arteries were extracted on day 5 after SAH. As a result, we found that administration of rhEPO could activate JAK2 and STAT3 in the basilar artery and decrease the apoptosis index of endothelial cells following SAH. Moreover, the anti-apoptotic genes such as bcl-2 and bcl-xL were up-regulated after the injections of rhEPO. In conclusion, the therapeutic effect of rhEPO on the subsequent vasospasm after SAH may relate to its inhibition on the endothelial apoptosis in the cerebral arteries, which may be mediated in part by JAK2/STAT3 signaling pathway.

Topics: Animals; Apoptosis; Basilar Artery; bcl-X Protein; Endothelium, Vascular; Erythropoietin; Humans; Janus Kinase 2; Male; Proto-Oncogene Proteins c-bcl-2; Rabbits; Random Allocation; Recombinant Proteins; RNA, Messenger; Signal Transduction; STAT3 Transcription Factor; Subarachnoid Hemorrhage; Up-Regulation; Vasospasm, Intracranial

The authors investigated the hemodynamic effects of recombinant human erythropoietin (rhEPO) after subarachnoid hemorrhage (SAH) in rabbits.. The authors used male New Zealand White rabbits in this study divided into the following groups: SAH plus saline (16 rabbits), SAH plus low-dose rhEPO (16 rabbits; 1500 IU/kg on Day 0 and 500 IU/kg on Days 2 and 4), SAH plus high-dose rhEPO (10 rabbits; 1500 IU/kg on Days 0, 2, 4, and 6), and sham (6 rabbits). Computed tomography perfusion studies and CT angiography were performed for 1 hour after SAH on Day 0, and once each on Days 2, 4, 7, 9, and 16 after SAH. Assessments of neurological function and tissue histology were also performed.. The mortality rate was significantly lower after rhEPO treatment (12%) than after saline treatment (44%) (p < 0.05). Neurological outcomes in the low-dose and high-dose rhEPO groups were better than in the saline group after SAH (p < 0.05), and the cerebral blood flow in the high-dose rhEPO group was greater than that in the saline group (p < 0.05). The mean transit time was significantly lower on Days 2 and 4 in the low-dose and high-dose rhEPO groups than in the saline group, but increased significantly on Day 7 in both groups (p < 0.05). The hematocrit increased significantly from baseline values in the high-dose and low-dose rhEPO groups on Days 4 and 7, respectively (p < 0.05).. Treatment with rhEPO after experimental SAH is associated with improved cerebral blood flow and microcirculatory flow as reflected by lower mean transit times. Improved tissue perfusion correlated with reduced mortality and improved neurological outcomes. Further investigation of the impact of increasing hematocrit on hemodynamic changes is needed.

Topics: Angiography; Animals; Central Nervous System; Cerebellum; Dose-Response Relationship, Drug; Erythropoietin; Hematocrit; Male; Microcirculation; Models, Animal; Rabbits; Recombinant Proteins; Regional Blood Flow; Subarachnoid Hemorrhage

Topics: Animals; Disease Models, Animal; Endothelium, Vascular; Erythropoietin; Gene Expression Regulation; Mice; Mice, Knockout; Neuroprotective Agents; NF-E2-Related Factor 2; Nitric Oxide; Subarachnoid Hemorrhage

In the present study, the effect of subarachnoid hemorrhage (SAH) on the phosphorylation of endothelial NO synthase (eNOS) and the ability of recombinant erythropoietin (Epo) to augment this vasodilator mechanism in the spastic arteries were studied.. Recombinant adenoviral vectors (10(9) plaque-forming units per animal) encoding genes for human Epo (AdEpo), and beta-galactosidase were injected immediately after injection of autologous arterial blood into the cisterna magna (day 0) of rabbits. Cerebral angiography was performed on day 0 and day 2, and basilar arteries were harvested for Western blots, measurement of cGMP levels, and analysis of vasomotor functions.. Injection of autologous arterial blood into cisterna magna resulted in significant vasospasm of the basilar arteries. Despite the narrowing of arterial diameter and reduced expression of eNOS, expressions of phosphorylated protein kinase B (Akt) and phosphorylated eNOS were significantly increased in spastic arteries. Gene transfer of AdEpo reversed the vasospasm. AdEpo-transduced basilar arteries demonstrated significant augmentation of the endothelium-dependent relaxations to acetylcholine, whereas the relaxations to an NO donor, 2-(N,N-diethylamino)diazenolate-2-oxide sodium salt, were not affected. Transduction with AdEpo further increased the expression of phosphorylated Akt and eNOS and elevated basal levels of cGMP in the spastic arteries.. Phosphorylation of eNOS appears to be an adaptive mechanism activated during development of vasospasm. The vascular protective effect of Epo against cerebral vasospasm induced by SAH may be mediated in part by phosphorylation of Akt/eNOS.

Topics: Animals; Cerebral Angiography; Endothelium, Vascular; Erythropoietin; Gene Transfer Techniques; Male; Nitric Oxide Synthase; Phosphorylation; Rabbits; Recombinant Proteins; Subarachnoid Hemorrhage; Up-Regulation; Vasospasm, Intracranial

Recent years' research has revealed a specific, neuroprotective erythropoietin (EPO) system in the central nervous system (CNS) that is upregulated by hypoxia. The presence and dynamics of EPO in the cerebrospinal fluid (CSF) of patients with subarachnoid haemorrhage (SAH) has not been investigated. We collected a total of 83 corresponding serum and CSF samples from 18 patients with aneurysmal SAH and compared the concentrations of EPO with those of blood-derived markers of blood-brain barrier function (albumin, transferrin, alpha(2)-macroglobulin) and with those of proteins with well-known CNS synthesis (prealbumin, apolipoprotein E). The EPO concentration in CSF was 0.93 (0.82) mU/ml (median and inter-quartile range). Nine patients presented CSF-EPO values above 1 mU/ml. CSF levels did not correlate with serum concentrations and were independent of blood-brain barrier integrity suggesting a synthesis in CNS rather than a blood-derived origin. Furthermore, the median CSF:serum ratio (Q(protein)) of EPO was similar to those of prealbumin and apolipoprotein E, and much higher than those of albumin, transferrin and alpha(2)-macroglobulin. When the Q(protein) of all proteins were plotted against Q(albumin), EPO showed dynamics similar to CNS-derived proteins. Our data indicate that EPO in the CSF of patients with aneurysmal SAH originates mainly from the CNS.

Topics: Adult; Aged; Brain; Erythropoietin; Female; Humans; Male; Middle Aged; Statistics, Nonparametric; Subarachnoid Hemorrhage

Systemic administration of recombinant erythropoietin (EPO) has been demonstrated to mediate neuroprotection. This effect of EPO may in part rely on a beneficial effect on cerebrovascular dysfunction leading to ischaemic neuronal damage. We investigated the in vivo effects of subcutaneously administered recombinant EPO on impaired cerebral blood flow (CBF) autoregulation after experimental subarachnoid haemorrhage (SAH). Four groups of male Sprague-Dawley rats were studied: group A, sham operation plus vehicle; group B, sham operation plus EPO; group C, SAH plus vehicle; group D, SAH plus EPO. SAH was induced by injection of 0.07 ml of autologous blood into the cisterna magna. EPO (400 iu kg(-1) s.c.) or vehicle was given immediately after the subarachnoid injection of blood or saline. Forty-eight hours after the induction of SAH, CBF autoregulatory function was evaluated using the intracarotid (133)Xe method. CBF autoregulation was preserved in both sham-operated groups (lower limits of mean arterial blood pressure: 91+/-3 and 98+/-3 mmHg in groups A and B, respectively). In the vehicle treated SAH-group, autoregulation was abolished and the relationship between CBF and blood pressure was best described by a single linear regression line. A subcutaneous injection of EPO given immediately after the induction of SAH normalized autoregulation of CBF (lower limit in group D: 93+/-4 mmHg, NS compared with groups A and B). Early activation of endothelial EPO receptors may represent a potential therapeutic strategy in the treatment of cerebrovascular perturbations after SAH.

Topics: Animals; Blood Pressure; Cerebrovascular Circulation; Erythropoietin; Homeostasis; Injections, Subcutaneous; Male; Rats; Rats, Sprague-Dawley; Subarachnoid Hemorrhage

Results of recent studies indicate that erythropoietin (EPO) produces a neuroprotective effect on experimental subarachnoid hemorrhage (SAH). It has been reported that S-100 protein levels increase in cerebrospinal fluid (CSF) after SAH, providing a highly prognostic indication of unfavorable outcome. This study was conducted to validate further the findings of S-100 protein as an index of brain damage and to assess whether treatment with recombinant human EPO (rhEPO) would limit the increase of S-100 protein level in CSF following experimental SAH.. Thirty-two rabbits were each assigned to one of four groups: Group 1, control; Group 2, SAH; Group 3, SAH plus placebo; and Group 4, SAH plus rhEPO (each group consisted of eight rabbits). The rhEPO and placebo were administered to the rabbits after SAH had been induced, and S-100 protein levels in the CSF of these animals were measured at 24, 48, and 72 hours after the experimental procedure. In each group of animals levels of S-100 protein were compared with the mortality rate, neurological outcome, and neuronal ischemic damage. High S-100 protein levels were found in rabbits in Groups 2 and 3, which exhibited poor neurological status and harbored a high number of damaged cortical neurons. Favorable neurological outcome and significant reductions in total numbers of damaged neurons were observed in animals in Group 4 in which there were significantly lower S-100 protein concentrations compared with animals in Groups 2 and 3 (p < 0.001).. The results of this study support the concept that determination of the S-100 protein level in CSF has prognostic value after SAH. The findings also confirm that rhEPO acts as a neuroprotective agent during experimental SAH.

Topics: Animals; Brain; Brain Damage, Chronic; Erythropoietin; Humans; Male; Neurologic Examination; Neurons; Neuroprotective Agents; Rabbits; Recombinant Proteins; S100 Proteins; Subarachnoid Hemorrhage

Cerebral vasospasm and ischemic damage are important causes of mortality and morbidity in patients affected by aneurysmal subarachnoid hemorrhage (SAH). Recently, i.p. administration of recombinant human erythropoietin (r-Hu-EPO) has been shown to exert a neuroprotective effect during experimental SAH. The present study was conducted to evaluate further the effect of r-Hu-EPO administration after SAH in rabbits on neurological outcome, degree of basilar artery spasm, and magnitude of neuronal ischemic damage. Experimental animals were divided into six groups: group 1 (n = 8), control; group 2 (n = 8), control plus placebo; group 3 (n = 8), control plus r-Hu-EPO; group 4 (n = 8), SAH; group 5 (n = 8), SAH plus placebo; group 6 (n = 8), SAH plus r-Hu-EPO. r-Hu-EPO, at a dose of 1,000 units/kg, and placebo were injected i.p. starting 5 min after inducing SAH and followed by clinical and pathological assessment 72 h later. Systemic administration of r-Hu-EPO produced significant increases in cerebrospinal fluid EPO concentrations (P < 0.001), and reduced vasoconstriction of the basilar artery (P < 0.05), ischemic neuronal damage (P < 0.001), and subsequent neurological deterioration (P < 0.05). These observations suggest that r-Hu-EPO may provide an effective treatment to reduce the post-SAH morbidity.

Topics: Animals; Erythropoietin; Humans; Hydrogen-Ion Concentration; Neurons; Perfusion; Rabbits; Recombinant Proteins; Subarachnoid Hemorrhage; Time Factors

Acute cerebral vasoconstriction and subsequent brain ischemia, often occurring in the early phase of subarachnoid hemorrhage (SAH), are critical problems in the management of patients affected by ruptured intracranial aneurysms. It is known that nitric oxide (NO) decreases during SAH with impairment of cerebrovascular relaxation, and glutamate is mainly involved in the consequent brain ischemic damage. Recently, erythropoietin (EPO) has shown to exert a neuroprotective effect during cerebral ischemia by enhancing the NO system activity. In the present study the effect of systemic administration of recombinant human erythropoietin (rHuEPO) has been investigated in a rabbit model of SAH.. Thirty-two rabbits were assigned to four groups: 1) Control; 2) SAH; 3) SAH plus placebo; 4) SAH plus rHuEPO. Experimental SAH was induced by injecting autologous blood into the cisterna magna. rHuEPO, at a dose of 1000 IU/kg, and placebo were given 5 minutes after SAH. Administration was repeated three times during 24 hours. The animals were killed 24 hours after SAH by a perfusion-fixation method. Luminal cross-sections of the basilar artery were measured by computer-assisted morphometric analysis. Ischemic injury was histologically evaluated by analysis of the frequency of ischemia-induced damaged cortical neurons.. Administration of rHuEPO significantly reversed the vasoconstriction of the basilar artery in Group 4 compared with the other groups (p<0.05). Histological examination showed a significant reduction in total damaged neurons count in Group 4 compared with the other groups (p<0.01).. These results suggest that rHuEPO is effective in attenuating acute cerebral vasoconstriction and ischemic brain injury following experimental SAH.

Topics: Animals; Brain Ischemia; Cerebrovascular Circulation; Disease Models, Animal; Erythropoietin; Glutamic Acid; Humans; Male; Neuroprotective Agents; Nitric Oxide; Rabbits; Recombinant Proteins; Subarachnoid Hemorrhage; Vasoconstriction

To ascertain in vivo whether recombinant human erythropoietin has a neuroprotective effect on the cortex during subarachnoid hemorrhage, 56 rabbits were divided into the following groups: Group 1 control sham operated plus placebo (n=14; saline solution - NaCl 0.9%); Group 2 control sham operated plus recombinant human erythropoietin (n=14); Group 3 subarachnoid hemorrhage plus placebo (n=14); Group 4 subarachnoid hemorrhage plus recombinant human erythropoietin (n=14; intraperitoneal administration of recombinant human erythropoietin immediately after inducing subarachnoid hemorrhage). In none of the Groups 1 and 2 animals was subarachnoid hemorrhage induced. In Group 3 rabbits, an increase in locomotor activity (open field apparatus) was observed 24, 48 and 72 h after surgery, and the mortality rate was 42.9% within 72 h after surgery, and, no increase in locomotor activity was observed in Group 4 rabbits, which survived for at least 72 h. Our findings suggest that recombinant human erythropoietin may be of benefit in the treatment of subarachnoid hemorrhage.

Topics: Animals; Erythropoietin; Female; Male; Motor Activity; Neuroprotective Agents; Rabbits; Recombinant Proteins; Subarachnoid Hemorrhage

Erythropoietin exerts a neuroprotective effect during cerebral ischemia. We investigated the effect of systemic administration of recombinant human erythropoietin in a rabbit model of subarachnoid hemorrhage-induced acute cerebral ischemia. The animals were divided into three groups: group 1, subarachnoid hemorrhage; group 2, subarachnoid hemorrhage plus placebo; group 3, subarachnoid hemorrhage plus recombinant human erythropoietin (each group, n=8). Experimental subarachnoid hemorrhage was produced by injecting autologous blood into the cisterna magna. Treatment with recombinant human erythropoietin and placebo was started 5 min after subarachnoid hemorrhage and was continued every 8 h for 24 h. Before the animals were killed, erythropoietin concentration was measured in the cerebrospinal fluid. The rabbits were killed 24 h after subarachnoid hemorrhage and ischemic brain injury was histologically evaluated. In group 3, the concentration of erythropoietin in the cerebrospinal fluid was significantly increased and a significant reduction in cortical necrotic neuron count was also observed. These findings may encourage the use of erythropoietin in the treatment of cerebral ischemia that often occurs in the early stage of subarachnoid hemorrhage.

Topics: Animals; Blood-Brain Barrier; Brain Ischemia; Calcium; Erythropoietin; Male; Rabbits; Recombinant Proteins; Subarachnoid Hemorrhage