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Thakkar P, McGregor A, Barber PA, Paton JF, Barrett C, McBryde F. Hypertensive Response to Ischemic Stroke in the Normotensive Wistar Rat. Stroke 2019; 50:2522-2530. [DOI: 10.1161/strokeaha.119.026459] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Over 80% of ischemic stroke patients show an abrupt increase in arterial blood pressure in the hours and days following ischemic stroke. Whether this poststroke hypertension is beneficial or harmful remains controversial and the underlying physiological basis is unclear.
Methods—
To investigate the dynamic cardiovascular response to stroke, adult Wistar rats (n=5–8 per group, 393±34 g) were instrumented with telemeters to blood pressure, intracranial pressure, renal sympathetic nerve activity, and brain tissue oxygen in the predicted penumbra (P
o
2
). After 2 weeks of recovery, cardiovascular signals were recorded for a 3-day baseline period, then ischemic stroke was induced via transient middle cerebral artery occlusion, or sham surgery. Cardiovascular signals were then recorded for a further 10 days, and the functional sensorimotor recovery assessed using the cylinder and sticky dot tests.
Results—
Baseline values of all variables were similar between groups. Compared to sham, in the 2 days following stroke middle cerebral artery occlusion produced an immediate, transient rise above baseline in mean blood pressure (21±3 versus 2±4 mm Hg;
P
<0.001), renal sympathetic nerve activity (54±11% versus 7±4%;
P
=0.006), and cerebral perfusion pressure (12±5 versus 1±4;
P
≤0.001). Intracranial pressure increased more slowly, peaking 3 days after middle cerebral artery occlusion (14±6 versus −1±1 mm Hg;
P
<0.001). Treating with the antihypertensive agent nifedipine after stroke (1.5–0.75 mg/kg per hour SC) ameliorated poststroke hypertension (12±3 mm Hg on day 1;
P
=0.041), abolished the intracranial pressure increase (3±1;
P
<0.001) and reduced cerebral perfusion pressure (10±3 mm Hg;
P
=0.017). Preventing poststroke hypertension affected neither the recovery of sensorimotor function nor infarct size.
Conclusions—
These findings suggest that poststroke hypertension is immediate, temporally matched to an increase in sympathetic outflow, and elevates cerebral perfusion pressure for several days after stroke, which may enhance cerebral perfusion. Preventing poststroke hypertension does not appear to worsen prognosis after stroke in young, normotensive, and otherwise healthy rats.
Visual Overview—
An online
visual overview
is available for this article.
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Affiliation(s)
- Pratik Thakkar
- From the Department of Physiology (P.T., J.F.R.P., C.B., F.M.), School of Medical Sciences, University of Auckland, New Zealand
| | - Ailsa McGregor
- School of Pharmacy, University of Otago, Dunedin, New Zealand (A.M.)
| | - Paul Alan Barber
- Centre for Brain Research (P.A.B.), School of Medical Sciences, University of Auckland, New Zealand
| | - Julian F.R. Paton
- From the Department of Physiology (P.T., J.F.R.P., C.B., F.M.), School of Medical Sciences, University of Auckland, New Zealand
| | - Carolyn Barrett
- From the Department of Physiology (P.T., J.F.R.P., C.B., F.M.), School of Medical Sciences, University of Auckland, New Zealand
| | - Fiona McBryde
- From the Department of Physiology (P.T., J.F.R.P., C.B., F.M.), School of Medical Sciences, University of Auckland, New Zealand
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Phelan C, Alaigh V, Fortunato G, Staff I, Sansing L. Effect of β-Adrenergic Antagonists on In-Hospital Mortality after Ischemic Stroke. J Stroke Cerebrovasc Dis 2015; 24:1998-2004. [PMID: 26163891 DOI: 10.1016/j.jstrokecerebrovasdis.2015.04.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 03/25/2015] [Accepted: 04/08/2015] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Ischemic stroke accounts for 85%-90% of all strokes and currently has very limited therapeutic options. Recent studies of β-adrenergic antagonists suggest they may have neuroprotective effects that lead to improved functional outcomes in rodent models of ischemic stroke; however, there are limited data in patients. We aimed to determine whether there was an improvement in mortality rates among patients who were taking β-blockers during the acute phase of their ischemic stroke. METHODS A retrospective analysis of a prospectively collected database of ischemic stroke patients was performed. Patients who were on β-adrenergic antagonists both at home and during the first 3 days of hospitalization were compared with patients who were not on β-adrenergic antagonists to determine the association with patient mortality rates. RESULTS The study included a patient population of 2804 patients. In univariate analysis, use of β-adrenergic antagonists was associated with older age, atrial fibrillation, hypertension, and more-severe initial stroke presentation. Despite this, multivariable analysis revealed a reduction in in-hospital mortality among patients who were treated with β-adrenergic antagonists (odds ratio, .657; 95% confidence interval, .655-.658). CONCLUSIONS The continuation of home β-adrenergic antagonist medication during the first 3 days of hospitalization after an ischemic stroke is associated with a decrease in patient mortality. This supports the work done in rodent models suggesting neuroprotective effects of β-blockers after ischemic stroke.
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Affiliation(s)
| | - Vivek Alaigh
- University of Connecticut School of Medicine, Farmington
| | | | - Ilene Staff
- Research Program, Hartford Hospital, Hartford
| | - Lauren Sansing
- University of Connecticut School of Medicine, Farmington; Department of Neurology, Hartford Hospital, University of Connecticut Health Center, Farmington, CT.
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Panahpour H, Nekooeian AA, Dehghani GA. Candesartan attenuates ischemic brain edema and protects the blood-brain barrier integrity from ischemia/reperfusion injury in rats. IRANIAN BIOMEDICAL JOURNAL 2015; 18:232-8. [PMID: 25326022 PMCID: PMC4225063 DOI: 10.6091/ibj.13672.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Background: Angiotensin II (Ang II) has an important role on cerebral microcirculation; however, its direct roles in terms of ischemic brain edema need to be clarified. This study evaluated the role of central Ang II by using candesartan, as an AT1 receptor blocker, in the brain edema formation and blood-brain barrier (BBB) disruption caused by ischemia/reperfusion (I/R) injuries in rat. Methods: Rats were exposed to 60-min middle cerebral artery (MCA) occlusion. Vehicle and non-hypotensive doses of candesartan (0.1 mg/kg) were administered one hour before ischemia. Neurological dysfunction scoring was evaluated following 24 h of reperfusion. Animals were then decapitated under deep anesthesia for the assessments of cerebral infarct size, edema formation, and BBB permeability. Results: The outcomes of 24 h reperfusion after 60-min MCA occlusion were severe neurological disability, massive BBB disruption (Evans blue extravasation = 12.5 ± 1.94 µg/g tissue), 4.02% edema, and cerebral infarction (317 ± 21 mm3). Candesartan at a dose of 0.1 mg/kg, without changing arterial blood pressure, improved neurological dysfunction scoring together with significant reductions in BBB disruption (54.9%), edema (59.2%), and cerebral infarction (54.9%). Conclusions: Inactivation of central AT1 receptors, if not accompanied with arterial hypotension, protected cerebral micro-vasculatures from damaging effects of acute stroke.
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Affiliation(s)
- Hamdollah Panahpour
- Dept. of Physiology and Pharmacology, Medical School, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Ali Akbar Nekooeian
- Dept. of Pharmacology, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Gholam Abbas Dehghani
- Dept. of Physiology, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
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Aromatic Amines Exert Contrasting Effects on the Anticoagulant Effect of Acetaldehyde upon APTT. Adv Hematol 2014; 2014:735751. [PMID: 25548568 PMCID: PMC4274862 DOI: 10.1155/2014/735751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 11/17/2022] Open
Abstract
The pharmacological effects of amphetamine, procaine, procainamide, DOPA, isoproterenol, and atenolol upon activated partial thromboplastin time in the absence and presence of acetaldehyde have been investigated. In the absence of acetaldehyde, amphetamine and isoproterenol exhibit a procoagulant effect upon activated partial thromboplastin time, whereas atenolol and procaine display anticoagulant effects upon activated partial thromboplastin time. DOPA and procainamide do not alter activated partial thromboplastin time. Premixtures of procaine with acetaldehyde produce an additive anticoagulant effect on activated partial thromboplastin time, suggesting independent action of these compounds upon clotting factors. Premixtures of amphetamine with acetaldehyde, as well as atenolol with acetaldehyde, generate a detoxication of the anticoagulant effect of acetaldehyde upon activated partial thromboplastin time. A similar statistically significant decrease in activated partial thromboplastin time is seen when procainamide is premixed with acetaldehyde for 20 minutes at room temperature. Premixtures of DOPA and isoproterenol with acetaldehyde do not affect an alteration in activated partial thromboplastin time relative to acetaldehyde alone. Hence, a selective interaction of atenolol, procaine, and amphetamine with acetaldehyde to produce detoxication of the acetaldehyde is suggested, undoubtedly due to the presence of amino, hydroxyl, or amide groups in these drugs.
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Interplay between brain stem angiotensins and monocyte chemoattractant protein-1 as a novel mechanism for pressor response after ischemic stroke. Neurobiol Dis 2014; 71:292-304. [PMID: 25131447 DOI: 10.1016/j.nbd.2014.08.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Revised: 07/03/2014] [Accepted: 08/02/2014] [Indexed: 11/20/2022] Open
Abstract
Pressor response after stroke commonly leads to early death or susceptibility to stroke recurrence, and detailed mechanisms are still lacking. We assessed the hypothesis that the renin-angiotensin system contributes to pressor response after stroke by differential modulation of the pro-inflammatory chemokine monocyte chemoattractant protein-1 (MCP-1) in the rostral ventrolateral medulla (RVLM), a key brain stem site that maintains blood pressure. We also investigated the beneficial effects of a novel renin inhibitor, aliskiren, against stroke-elicited pressor response. Experiments were performed in male adult Sprague-Dawley rats. Stroke induced by middle cerebral artery occlusion elicited significant pressor response, accompanied by activation of angiotensin II (Ang II)/type I receptor (AT1R) and AT2R signaling, depression of Ang-(1-7)/MasR and Ang IV/AT4R cascade, alongside augmentation of MCP-1/C-C chemokine receptor 2 (CCR2) signaling and neuroinflammation in the RVLM. Stroke-elicited pressor response was significantly blunted by antagonism of AT1R, AT2R or MCP-1/CCR2 signaling, and eliminated by applying Ang-(1-7) or Ang IV into the RVLM. Furthermore, stroke-activated MCP-1/CCR2 signaling was enhanced by AT1R and AT2R activation, and depressed by Ang-(1-7)/MasR and Ang IV/AT4R cascade. Aliskiren inhibited stroke-elicited pressor response via downregulating MCP-1/CCR2 activity and reduced neuroinflammation in the RVLM; these effects were potentiated by Ang-(1-7) or Ang IV. We conclude that whereas Ang II/AT1R or Ang II/AT2R signaling in the brain stem enhances, Ang-(1-7)/MasR or Ang IV/AT4R antagonizes pressor response after stroke by differential modulations of MCP-1 in the RVLM. Furthermore, combined administration of aliskiren and Ang-(1-7) or Ang IV into the brain stem provides more effective amelioration of stroked-induced pressor response.
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Ström JO, Ingberg E, Theodorsson A, Theodorsson E. Method parameters' impact on mortality and variability in rat stroke experiments: a meta-analysis. BMC Neurosci 2013; 14:41. [PMID: 23548160 PMCID: PMC3637133 DOI: 10.1186/1471-2202-14-41] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 03/22/2013] [Indexed: 12/14/2022] Open
Abstract
Background Even though more than 600 stroke treatments have been shown effective in preclinical studies, clinically proven treatment alternatives for cerebral infarction remain scarce. Amongst the reasons for the discrepancy may be methodological shortcomings, such as high mortality and outcome variability, in the preclinical studies. A common approach in animal stroke experiments is that A) focal cerebral ischemia is inflicted, B) some type of treatment is administered and C) the infarct sizes are assessed. However, within this paradigm, the researcher has to make numerous methodological decisions, including choosing rat strain and type of surgical procedure. Even though a few studies have attempted to address the questions experimentally, a lack of consensus regarding the optimal methodology remains. Methods We therefore meta-analyzed data from 502 control groups described in 346 articles to find out how rat strain, procedure for causing focal cerebral ischemia and the type of filament coating affected mortality and infarct size variability. Results The Wistar strain and intraluminal filament procedure using a silicone coated filament was found optimal in lowering infarct size variability. The direct and endothelin methods rendered lower mortality rate, whereas the embolus method increased it compared to the filament method. Conclusions The current article provides means for researchers to adjust their middle cerebral artery occlusion (MCAo) protocols to minimize infarct size variability and mortality.
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Affiliation(s)
- Jakob O Ström
- Department of Clinical and Experimental Medicine, Clinical Chemistry, Faculty of Health Sciences, Linköping University, County Council of Östergötland, Linköping, Sweden.
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Gopal K, Nagarajan P, Raj TA, Jahan P, Ganapathy HS, Mahesh Kumar MJ. Effect of dietary β carotene on cerebral aneurysm and subarachnoid haemorrhage in the brain apo E-/- mice. J Thromb Thrombolysis 2012; 32:343-55. [PMID: 21786025 DOI: 10.1007/s11239-011-0620-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Atherosclerosis will lead to stenosis/occlusion in the lumen of various arteries of living body. This can lead various conditions including myocardial infarction, cerebral infarction/aneurysm and peripheral artery disease. Ang II is believed to be an important regulatory peptide involved in maintaining cardiovascular homeostasis and pathogenesis of various cardiovascular diseases. Matrix metalloproteinase's (MMPs), adhesion molecules and plasminogen systems are involved in the inflammatory reaction of various blood vessels as well as pathogenesis of cerebro vasuclar disease in apo E(-/-) mice during angiotensin II injection. The present study analyses the role of ang II in development of cerebral aneurysm and also evaluated the mRNA levels of MMPs, adhesion molecules, plasminogen systems and peroxisome proliferators-associated receptors in the brain of apo E(-/-) mouse during the progression of cerebral aneurysm and ischemic conditions. Also, this study evaluates the role of dietary β carotene on cerebrovascular disease. Serum total cholesterol (TC), Low density lipoprotein (LDL) and triglyceride (TG) levels were significantly increased in angiotensin II treated animals and further β carotene supplementation reduces TC but does not affect the triglyceride and LDL levels. Circulating levels of macrophages were significantly increased in angiotensin treated animals and further beta carotene supplementation significantly reduced the circulating macrophages. Cerebro meningeous aneurysm, subarachnoid haemorrhage, multiple foci of infarction, necrosis and infiltration of inflammatory cells were observed in the cerebral hemispheres of ang II treated animals, however, infarction size were reduced and no aneurysm, inflammatory foci was observed in β carotene treated animals. Real time analysis showed down regulation of mRNA levels of MMP 2, uPA, PAI, PPAR-A, MCSF1 and up regulation of tPA and MCP-1 in the brain during the progression of cerebral aneurysm and β carotene supplementation to bring to normal expression levels of all the candidate genes for cerebrovascular diseases. Based on above results, Ang II may induced cerebral aneurysm, ischemia/infarction on brain through RAS system by down regulating the mRNA levels of MMP 2, uPA, PAI, PPAR-A, MCSF1 and up regulating tPA and MCP-1 and β carotene attenuates the disease condition and bring down to normal expression levels of above genes.
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Affiliation(s)
- K Gopal
- Small Animal Facility, Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India
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Nagai M, Terao S, Vital SA, Rodrigues SF, Yilmaz G, Granger DN. Role of blood cell-associated angiotensin II type 1 receptors in the cerebral microvascular response to ischemic stroke during angiotensin-induced hypertension. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2011; 3:15. [PMID: 22087550 PMCID: PMC3240825 DOI: 10.1186/2040-7378-3-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 11/16/2011] [Indexed: 01/28/2023]
Abstract
BACKGROUND Angiotensin II type 1 receptor (AT1R) blockers lower the incidence of ischemic stroke in hypertensive patients and attenuate brain inflammation and injury in animal models. Although AT1R on both blood cells (BC) and vascular endothelial cells (EC) can be activated by angiotensin II (Ang II) to elicit inflammation, little is known about the relative contributions of AT1R expressed on BC and EC to the brain injury responses to ischemia and reperfusion (I/R) in the setting of angiotensin-induced hypertension. METHODS The contributions of BC- and EC-associated AT1R to I/R-induced brain inflammation and injury were evaluated using wild type (WT), AT1aR-/-, and bone marrow chimera mice with either a BC+/EC+ (WT→WT) or BC-/EC+ (AT1aR-/-→WT) distribution of AT1aR. The adhesion of leukocytes and platelets in venules, blood brain barrier (BBB) permeability and infarct volume were monitored in postischemic brain of normotensive and Ang II-induced hypertensive mice. RESULTS The inflammatory (blood cell adhesion) and injury (BBB permeability, infarct volume) responses were greatly exaggerated in the presence of Ang II-induced hypertension. The Ang II-enhanced responses were significantly blunted in AT1aR-/- mice. A similar level of protection was noted in AT1aR-/- →WT mice for BBB permeability and infarct volume, while less or no protection was evident for leukocyte and platelet adhesion, respectively. CONCLUSIONS BC- and EC-associated AT1aR are both involved in the brain injury responses to ischemic stroke during Ang II-hypertension, with EC AT1aR contributing more to the blood cell recruitment response and BC AT1aR exerting a significant influence on the BBB disruption and tissue necrosis elicited by I/R.
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Affiliation(s)
- Mutsumi Nagai
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Satoshi Terao
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Shantel A Vital
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Stephen F Rodrigues
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Gokhan Yilmaz
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - D Neil Granger
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
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Gaur V, Kumar A. Neuroprotective potentials of candesartan, atorvastatin and their combination against stroke induced motor dysfunction. Inflammopharmacology 2011; 19:205-14. [PMID: 21061073 DOI: 10.1007/s10787-010-0068-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 10/19/2010] [Indexed: 01/18/2023]
Abstract
Cerebral ischaemia is a leading cause of death and disability. The objective of the present investigation was to explore the neuroprotective potentials of candesartan and atorvastatin alone and their combination against the cerebral ischaemia induced behavioral, biochemical, and mitochondrial dysfunction. Male Wistar rats (200-220 g) were subjected to bilateral common carotid artery occlusion for 30 min followed by 24 h reperfusion. Candesartan (0.1 and 0.3 mg/kg) and atorvastatin (10 and 20 mg/kg) were pretreated for 7 days before animals were subjected to ischaemia reperfusion injury. Various behavioral tests (locomotor activity and rotarod performance), biochemical parameters (Malondialdehyde levels, nitrite concentration, superoxide dismutase and catalase activity, redox ratio, and GST) and mitochondrial enzyme (Complex I, II, III, and IV) dysfunctions were measured in cerebral cortex, striatum and hippocampus of the ischaemic brain. Seven days candesartan (0.1 and 0.3 mg/kg) or atorvastatin (10 and 20 mg/kg) pretreatment significantly attenuated neurobehavioral alterations, oxidative damage and restored mitochondrial enzyme dysfunction as compared to control (I/R) group. Further, combined treatment of candesartan (0.1 mg/kg) and atorvastatin (10 mg/kg) significantly potentiated their protective effect which was significant as compared to their effect alone. Present study suggests the protective effect of candesartan and atorvastatin and their combination against ischaemia reperfusion induced behavioral and biochemical alterations in rats.
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Affiliation(s)
- Vaibhav Gaur
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Study, Panjab University, Chandigarh 160014, India
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