RESUMO
BACKGROUND: Eugenol has various curative properties. It affects the dilatation of cerebral arteries through voltage-dependent Ca2+ channel inhibition. This study is the first to explore the impact of eugenol on neuroprotection and vasospasm in an experimental subarachnoid hemorrhage (SAH) model. METHODS: Twenty-four adult male Sprague-Dawley rats were indiscriminately separated into 3 groups: the control group (n = 8), the SAH group (n = 8), and the eugenol group (n = 8). A double-bleeding method was used. The eugenol group received intracisternal eugenol (Sigma-Aldrich, St. Louis, MO, USA) at 30 µg/20 µl after induction of SAH. On the day 7, all groups were euthanized. Measurements were taken for basilar artery wall thickness, lumen diameter, serum endothelin-1 (ET-1), and caspase-3 levels. RESULTS: The eugenol group exhibited significantly lower wall thickness, ET-1, oxidative stress index, and caspase-3 levels compared to the SAH group. In comparison to the control group, the eugenol group showed a higher oxidative stress index along with higher ET-1 and caspase-3 levels, but these differences were not statistically significant. Wall thickness was significantly higher in the eugenol group than in the control group. CONCLUSIONS: This study represents the first literature exploration of intrathecal eugenol's impact on vasospasm induced after experimental SAH. Administration of intrathecal eugenol demonstrates a positive effect on the treatment of experimental vasospasm as well as on the reduction of oxidative stress and apoptosis.
Assuntos
Modelos Animais de Doenças , Eugenol , Ratos Sprague-Dawley , Hemorragia Subaracnóidea , Vasoespasmo Intracraniano , Animais , Eugenol/administração & dosagem , Eugenol/farmacologia , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/tratamento farmacológico , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/etiologia , Masculino , Ratos , Injeções Espinhais , Estresse Oxidativo/efeitos dos fármacos , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/patologia , Fármacos Neuroprotetores/administração & dosagem , Endotelina-1/sangue , Caspase 3/metabolismoRESUMO
BACKGROUND: Data from trials investigating the effects and risks of endovascular thrombectomy for the treatment of stroke due to basilar-artery occlusion are limited. METHODS: We conducted a multicenter, prospective, randomized, controlled trial of endovascular thrombectomy for basilar-artery occlusion at 36 centers in China. Patients were assigned, in a 2:1 ratio, within 12 hours after the estimated time of basilar-artery occlusion to receive endovascular thrombectomy or best medical care (control). The primary outcome was good functional status, defined as a score of 0 to 3 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]), at 90 days. Secondary outcomes included a modified Rankin scale score of 0 to 2, distribution across the modified Rankin scale score categories, and quality of life. Safety outcomes included symptomatic intracranial hemorrhage at 24 to 72 hours, 90-day mortality, and procedural complications. RESULTS: Of the 507 patients who underwent screening, 340 were in the intention-to-treat population, with 226 assigned to the thrombectomy group and 114 to the control group. Intravenous thrombolysis was used in 31% of the patients in the thrombectomy group and in 34% of those in the control group. Good functional status at 90 days occurred in 104 patients (46%) in the thrombectomy group and in 26 (23%) in the control group (adjusted rate ratio, 2.06; 95% confidence interval [CI], 1.46 to 2.91, P<0.001). Symptomatic intracranial hemorrhage occurred in 12 patients (5%) in the thrombectomy group and in none in the control group. Results for the secondary clinical and imaging outcomes were generally in the same direction as those for the primary outcome. Mortality at 90 days was 37% in the thrombectomy group and 55% in the control group (adjusted risk ratio, 0.66; 95% CI, 0.52 to 0.82). Procedural complications occurred in 14% of the patients in the thrombectomy group, including one death due to arterial perforation. CONCLUSIONS: In a trial involving Chinese patients with basilar-artery occlusion, approximately one third of whom received intravenous thrombolysis, endovascular thrombectomy within 12 hours after stroke onset led to better functional outcomes at 90 days than best medical care but was associated with procedural complications and intracerebral hemorrhage. (Funded by the Program for Innovative Research Team of the First Affiliated Hospital of USTC and others; ATTENTION ClinicalTrials.gov number, NCT04751708.).
Assuntos
Arteriopatias Oclusivas , Artéria Basilar , Procedimentos Endovasculares , Acidente Vascular Cerebral , Trombectomia , Humanos , Administração Intravenosa , Arteriopatias Oclusivas/complicações , Arteriopatias Oclusivas/tratamento farmacológico , Arteriopatias Oclusivas/mortalidade , Arteriopatias Oclusivas/cirurgia , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/cirurgia , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/etiologia , Isquemia Encefálica/cirurgia , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/métodos , Fibrinolíticos/administração & dosagem , Fibrinolíticos/efeitos adversos , Fibrinolíticos/uso terapêutico , Hemorragias Intracranianas/induzido quimicamente , Hemorragias Intracranianas/etiologia , Estudos Prospectivos , Qualidade de Vida , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/cirurgia , Trombectomia/efeitos adversos , Trombectomia/métodos , Terapia Trombolítica/efeitos adversos , Terapia Trombolítica/métodos , Resultado do Tratamento , Recuperação de Função FisiológicaRESUMO
BACKGROUND: The effects and risks of endovascular thrombectomy 6 to 24 hours after stroke onset due to basilar-artery occlusion have not been extensively studied. METHODS: In a trial conducted over a 5-year period in China, we randomly assigned, in a 1:1 ratio, patients with basilar-artery stroke who presented between 6 to 24 hours after symptom onset to receive either medical therapy plus thrombectomy or medical therapy only (control). The original primary outcome, a score of 0 to 4 on the modified Rankin scale (range, 0 to 6, with a score of 0 indicating no disability, 4 moderately severe disability, and 6 death) at 90 days, was changed to a good functional status (a modified Rankin scale score of 0 to 3, with a score of 3 indicating moderate disability). Primary safety outcomes were symptomatic intracranial hemorrhage at 24 hours and 90-day mortality. RESULTS: A total of 217 patients (110 in the thrombectomy group and 107 in the control group) were included in the analysis; randomization occurred at a median of 663 minutes after symptom onset. Enrollment was halted at a prespecified interim analysis because of the superiority of thrombectomy. Thrombolysis was used in 14% of the patients in the thrombectomy group and in 21% of those in the control group. A modified Rankin scale score of 0 to 3 (primary outcome) occurred in 51 patients (46%) in the thrombectomy group and in 26 (24%) in the control group (adjusted rate ratio, 1.81; 95% confidence interval [CI], 1.26 to 2.60; P<0.001). The results for the original primary outcome of a modified Rankin scale score of 0 to 4 were 55% and 43%, respectively (adjusted rate ratio, 1.21; 95% CI, 0.95 to 1.54). Symptomatic intracranial hemorrhage occurred in 6 of 102 patients (6%) in the thrombectomy group and in 1 of 88 (1%) in the control group (risk ratio, 5.18; 95% CI, 0.64 to 42.18). Mortality at 90 days was 31% in the thrombectomy group and 42% in the control group (adjusted risk ratio, 0.75; 95% CI, 0.54 to 1.04). Procedural complications occurred in 11% of the patients who underwent thrombectomy. CONCLUSIONS: Among patients with stroke due to basilar-artery occlusion who presented 6 to 24 hours after symptom onset, thrombectomy led to a higher percentage with good functional status at 90 days than medical therapy but was associated with procedural complications and more cerebral hemorrhages. (Funded by the Chinese National Ministry of Science and Technology; BAOCHE ClinicalTrials.gov number, NCT02737189.).
Assuntos
Arteriopatias Oclusivas , Artéria Basilar , Procedimentos Endovasculares , Acidente Vascular Cerebral , Trombectomia , Humanos , Arteriopatias Oclusivas/complicações , Arteriopatias Oclusivas/tratamento farmacológico , Arteriopatias Oclusivas/mortalidade , Arteriopatias Oclusivas/cirurgia , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/cirurgia , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/etiologia , Isquemia Encefálica/mortalidade , Isquemia Encefálica/cirurgia , Avaliação da Deficiência , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/métodos , Fibrinolíticos/efeitos adversos , Fibrinolíticos/uso terapêutico , Hemorragias Intracranianas/induzido quimicamente , Hemorragias Intracranianas/etiologia , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/cirurgia , Trombectomia/efeitos adversos , Trombectomia/métodos , Fatores de Tempo , Resultado do TratamentoRESUMO
The responsiveness of the basilar artery to intrinsic vasoactive substances is species-specific and can be a unique characteristic. We investigated the responsiveness of the bat (Rhinolophus ferrumequinum) basilar artery to noradrenaline (NA), 5-hydroxytryptamine (5-HT), angiotensin (Ang) II, bradykinin (BK), histamine (His), and acetylcholine (ACh). NA, 5-HT, Ang II, and BK induced contraction, whereas His and ACh induced relaxation, in a concentration-dependent manner. The NA cumulative concentration-response curve was shifted to the right in parallel with phentolamine (an α-antagonist). However, propranolol, a ß-antagonist, had no significant effect. The 5-HT curve was shifted to the right in parallel by ketanserin (a 5-HT2 antagonist) and methiothepin (a 5-HT1 and 5-HT2 antagonist). Losartan (an AT1 antagonist) shifted the Ang II curve to the right, whereas PD123319 (an AT2 antagonist) had no significant effect. L-NA, indomethacin, and des-Arg9-[Leu8]-BK (a B1 antagonist) did not significantly affect BK-induced contractions. HOE140 (a B2 antagonist) shifted the BK concentration-response curve to the right. The His curve was shifted to the right weakly by diphenhydramine (an H1 antagonist) and strongly by cimetidine (a H2 antagonist). ACh-induced relaxation was significantly inhibited by L-NA, atropine, and pFHHSiD (a muscarinic M3 antagonist), whereas pirenzepine and methoctramine (muscarinic M1 and M2 antagonists, respectively) showed no significant effects. At a resting vascular tone, L-NA-induced contraction and indomethacin induced relaxation. These results suggest that α-adrenergic, 5-HT1, 5-HT2, AT1, and B2 receptors might be important in arterial contraction, whereas M3 and H2 (>H1) receptors might modify these contractions, inducing relaxation.
Assuntos
Acetilcolina/farmacologia , Angiotensina II/farmacologia , Artéria Basilar/efeitos dos fármacos , Bradicinina/farmacologia , Quirópteros , Histamina/farmacologia , Norepinefrina/farmacologia , Serotonina/farmacologia , Animais , Agonistas dos Receptores Histamínicos/farmacologia , Agonistas do Receptor de Serotonina/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
Xiaoxuming decoction (XXMD) is a traditional Chinese herbal medicine (CHM) that is used for the treatment of stroke in China. Stroke injury damages the cerebral vasculature and disrupts the autoregulation of vasoconstriction and vasodilatation, which is crucial for maintaining constant cerebral blood flow (CBF). It has been reported that XXMD exerts a positive effect on cerebral circulation in animal models of stroke. However, the mechanisms underlying the regulatory effect of XXMD on vascular tone, and the interactions among the multiple components of XXMD, remain unclear. In this study, XXMD was found to induce relaxation of the basilar artery rings of rats precontracted by 5-hydroxytryptamine (5-HT) in vitro, in a dose-dependent manner. The modulation of vascular tone and the process of cerebral ischemia are mediated via the interactions between G protein-coupled receptors (GPCRs) and their ligands, including 5-HT, angiotensin II (Ang II), and urotensin II (UII). Thus, the potential synergistic effects of the different components of XXMD on the regulation of vasoconstriction and vasodilation were further investigated by molecular docking based on network pharmacology. We constructed and analyzed a database comprising 963 compounds of XXMD and studied the interactions between five vascular GPCRs (5-HT1A receptor (5-HT1AR), 5-HT1B receptor (5-HT1BR), Ang II type 1 receptor (AT1R), beta 2-adrenergic receptor (ß2-AR), and UII receptor (UTR)) and the various herbal constituents of XXMD using molecular docking. By constructing and analyzing the compound-target networks of XXMD, we found that Glycyrrhizae Radix et Rhizoma, Ginseng Radix et Rhizoma, and Paeoniae Radix Alba were the three major herbs that contained a large number of compounds with high docking scores. We additionally observed that several constituents of XXMD, including gallotannin, liquiritin apioside, nariutin, 1,2,3,4,6-pentagalloylglucose, folic acid, and ginsenoside Rb1, targeted multiple vascular GPCRs. Moreover, the interactions between the components of XXMD and the targets related to vascular tone constituted the comprehensive cerebrovascular regulatory function of XXMD and provided a material basis of the vasoregulatory function of XXMD. The study reports the contributions of various components of XXMD to the regulatory effects on vascular tone and provides scientific evidence for the multicomponent and multitargeting characteristics of XXMD.
Assuntos
Artéria Basilar/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Receptores Acoplados a Proteínas G/metabolismo , Animais , Isquemia Encefálica/tratamento farmacológico , Circulação Cerebrovascular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/metabolismo , Glycyrrhiza , Ligantes , Masculino , Medicina Tradicional Chinesa , Simulação de Acoplamento Molecular , Paeonia/metabolismo , Panax/metabolismo , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Serotonina/farmacologiaRESUMO
Cell-free hemoglobin (Hb) is a driver of disease progression in conditions with intravascular or localized hemolysis. Genetic and acquired anemias or emergency medical conditions such as aneurysmal subarachnoid hemorrhage involve tissue Hb exposure. Haptoglobin (Hp) captures Hb in an irreversible protein complex and prevents its pathophysiological contributions to vascular nitric oxide depletion and tissue oxidation. Preclinical proof-of-concept studies suggest that human plasma-derived Hp is a promising therapeutic candidate for several Hb-driven diseases. Optimizing the efficacy and safety of Hb-targeting biotherapeutics may require structural and functional modifications for specific indications. Improved Hp variants could be designed to achieve the desired tissue distribution, metabolism, and elimination to target hemolytic disease states effectively. However, it is critical to ensure that these modifications maintain the function of Hp. Using transient mammalian gene expression of Hp combined with co-transfection of the pro-haptoglobin processing protease C1r-LP, we established a platform for generating recombinant Hp-variants. We designed an Hpß-scaffold, which was expressed in this system at high levels as a monomeric unit (mini-Hp) while maintaining the key protective functions of Hp. We then used this Hpß-scaffold as the basis to develop an initial proof-of-concept Hp fusion protein using human serum albumin as the fusion partner. Next, a hemopexin-Hp fusion protein with bispecific heme and Hb detoxification capacity was generated. Further, we developed a Hb scavenger devoid of CD163 scavenger receptor binding. The functions of these proteins were then characterized for Hb and heme-binding, binding of the Hp-Hb complexes with the clearance receptor CD163, antioxidant properties, and vascular nitric oxide sparing capacity. Our platform is designed to support the generation of innovative Hb scavenger biotherapeutics with novel modes of action and potentially improved formulation characteristics, function, and pharmacokinetics.
Assuntos
Produtos Biológicos/metabolismo , Desenho de Fármacos/métodos , Haptoglobinas/metabolismo , Hemoglobinas/metabolismo , Hemopexina/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Artéria Basilar/efeitos dos fármacos , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Células HEK293 , Haptoglobinas/química , Haptoglobinas/genética , Heme/metabolismo , Hemoglobinas/química , Hemólise , Hemopexina/química , Hemopexina/genética , Humanos , Ligação Proteica , Receptores de Superfície Celular/metabolismo , Receptores Depuradores/metabolismo , Proteínas Recombinantes de Fusão/genética , Albumina Sérica Humana/química , Albumina Sérica Humana/genética , Albumina Sérica Humana/metabolismo , Suínos , Transfecção , Vasodilatação/efeitos dos fármacosRESUMO
Hypotonic stimulus enlarges cell volume and increased cell proliferation with the exact mechanisms unknown. Glucocorticoid-induced kinase-1 (SGK1) is a serine/threonine kinase that can be regulated by osmotic pressure. We have revealed that SGK1 was activated by hypotonic solution-induced lowering of intracellular Cl- concentration. Therefore, we further examined whether SGK1 mediated hypotonic solution-induced proliferation and the internal mechanisms in basilar smooth muscle cells (BASMCs). In the present study, BrdU incorporation assay, flow cytometry, western blotting were performed to evaluate cell viability, cell cycle transition, and the expression of cell cycle regulators and other related proteins. We found that silence of SGK1 largely blunted hypotonic challenge-induced increase in cell viability and cell cycle transition from G0/G1 phase to S phase, whereas overexpression of SGK1 showed the opposite effects. The effect of SGK1 on proliferation was related to the upregulation of cyclin D1 and cyclin E1, and the downregulation of p27 and p21, which is mediated by the interaction between SGK1 and cAMP responsive element-binding protein (CREB). Moreover, we overexpressed ClC-3 Cl- channel to further verify the role of SGK1 in low Cl- environment-induced proliferation. The results revealed that overexpression of ClC-3 further enhanced hypotonic solution-induced cell viability, cell cycle transition, and CREB activation, which were alleviated or potentiated by silencing or overexpression of SGK1. In summary, this study provides compelling evidences that SGK1, as a Cl--sensitive kinase, is a critical link between low osmotic pressure and proliferation in BASMCs, and shed a new light on the treatment of proliferation-associated cardiovascular diseases.
Assuntos
Proliferação de Células/efeitos dos fármacos , Canais de Cloreto/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Soluções Hipotônicas/farmacologia , Proteínas Imediatamente Precoces/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/enzimologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Canais de Cloreto/genética , Proteínas Imediatamente Precoces/genética , Masculino , Músculo Liso Vascular/enzimologia , Miócitos de Músculo Liso/enzimologia , Pressão Osmótica , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
Methyl palmitate (MP) is a fatty acid methyl ester. Our recent study indicated that adrenergic nerve-dependent functional sympathetic-sensory nerve interactions were abolished by MP in mesenteric arteries. However, the effect of MP on perivascular nerves and cerebral blood flow remains unclear. In this study, the increase in basilar arterial blood flow (BABF) after the topical application of nicotinic acetylcholine receptor agonists was measured using laser Doppler flowmetry in anesthetized rats. The choline (a selective α7-nicotinic acetylcholine receptor agonist)-induced increase in BABF was abolished by tetrodotoxin (a neurotoxin), NG -nitro-L-arginine (a nonselective NO synthase inhibitor), α-bungarotoxin (a selective α7-nicotinic acetylcholine receptor inhibitor), and chronic sympathetic denervation. In addition, the nicotine (a nicotinic acetylcholine receptor agonist)-induced increase in BABF was inhibited by MP in a concentration-dependent manner. The acetylcholine-induced increase in BABF was not affected by MP. The myography results revealed that nicotine-induced vasorelaxation was significantly inhibited by MP, but was reversed by chelerythrine (a protein kinase C inhibitor). MP-induced vasodilation was significantly greater in BA rings without endothelium compared to those with endothelium. Meanwhile, MP did not affect baseline BABF. Our results indicate that MP acts as a neuromodulator in the cerebral circulation where it activates the PKC pathway and causes a diminished nicotine-induced increase in blood flow in the brainstem, and that the vasorelaxation effect of MP may play a minor role.
Assuntos
Artéria Basilar , Tronco Encefálico , Neurotransmissores , Nicotina , Palmitatos , Receptores Nicotínicos , Animais , Artéria Basilar/diagnóstico por imagem , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/fisiologia , Tronco Encefálico/irrigação sanguínea , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/efeitos dos fármacos , Fluxometria por Laser-Doppler , Masculino , Neurotransmissores/farmacologia , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Palmitatos/farmacologia , Ratos , Receptores Nicotínicos/efeitos dos fármacos , Receptores Nicotínicos/fisiologia , Vasodilatação/efeitos dos fármacosRESUMO
OBJECTS: Cerebral vasospasm is an important event that occurs following subarachnoid hemorage which has significant mortality and morbidity. The goal in this study was to investigate the effect of pentoxifylline on vasospasm in an experimental subarachnoid hemorrhage model. METHODS: In this study, 20 male New Zeland White rabbits weighing 3000-3500 g were assigned randomly to four groups. Animals in group 1 served as controls. Animals in group two received only intravenous pentoxifylline injection 3 times in 12 h intervals. In group 3, SAH was induced and no injection was given. Animals in group 4 received intravenous pentoxifylline (6 mg/kg) injections 3 times at 12th, 24th and 36th hours after subarachnoid hemorrhage induction. All animals were sacrificed and basilar arteries were removed at 48th hour. Basilar artery vessel diameters, wall thicknesses and luminal section areas were measured with Spot for Windows version 4.1. Statistical analysis was performed using ANOVA and Kruskall-Wallis tests. RESULTS: Mean basilar artery luminal section areas and luminal diameters in group 4 were significantly higher compared to group 3 (p < 0.05). Basilar artery wall thicknesses and were found to be higher in group 3 than in other groups and this was also statistically significant (p < 0.05). CONCLUSION: Our study demonstrated that intravenous administration of pentoxifylline significantly decreases vasospasm after subarachnoid hemorrhage.
Assuntos
Pentoxifilina/administração & dosagem , Hemorragia Subaracnóidea/complicações , Vasoespasmo Intracraniano/tratamento farmacológico , Animais , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/patologia , Modelos Animais de Doenças , Masculino , Coelhos , Hemorragia Subaracnóidea/patologia , Vasoespasmo Intracraniano/complicações , Vasoespasmo Intracraniano/patologiaRESUMO
BACKGROUND: Adalimumab (ADA), which is a new-generation recombinant human monoclonal antibody for tumor necrosis factor α (TNFα), has strong anti-inflammatory effects. The role of enhanced inflammation is well established for the development and progression of cerebral vasospasm. Investigated in the present study is the probable ameliorating and neuroprotective effects of ADA in rabbits using a cerebral vasospasm model with biochemical and histopathological methods. METHODS: Thirty male New-Zealand white rabbits were randomly divided into control, subarachnoid hemorrhage (SAH) only and SAH plus ADA treatment groups. SAH was established as a single cisterna magna autologous arterial blood injection. ADA treatment was started just after intracisternal blood injection and continued for 72 hours once a day. The animals were sacrificed 72 hours after the induction of SAH, serum and brainstem tissue obtained for investigations. RESULTS: Brainstem tissue and plasma levels of tumor necrosis factor-alpha and Interleukin-1ß, brainstem tissue Matrix metalloproteinase-9 levels increased after SAH and partly decreased after treatment. Plasma levels of brain-derived neurotrophic factor decreased after SAH and partly restored after treatment. ADA treatment significantly increased the mean cross-sectional area of the vasospastic basilar arteries, reduced the basilar artery wall thickness and also ameliorates enhanced endothelial apoptosis. CONCLUSION: Findings obtained in this study suggest that ADA is an effective neuroprotective agent for ameliorating cerebral vasospasm in experimental rabbit vasospasm.
Assuntos
Adalimumab/farmacologia , Anti-Inflamatórios/farmacologia , Fármacos Neuroprotetores/farmacologia , Hemorragia Subaracnóidea , Vasoespasmo Intracraniano , Animais , Artéria Basilar/efeitos dos fármacos , Modelos Animais de Doenças , Masculino , CoelhosRESUMO
BACKGROUND: Cerebral vasospasm (CVS) remains a major cause of delayed cerebral ischaemia following aneurysmal subarachnoid haemorrhage (SAH), making it a life-threatening type of stroke with high morbidity and mortality. Endothelin-1 is known as key player mediating a strong vasocontractile effect. Interestingly, losartan restores the impaired vasorelaxative ET(B1) receptor function in a non-competitive direct fashion. With this study, we aimed to investigate a potential losartan-dependent vasodilatory effect vice versa by inhibiting NO release through L-NAME, thus pushing forward concepts to alleviate vasospasm and possibly prevent ischaemia and neurodegeneration. METHODS: Cerebral vasospasm was induced by the use of an established double-injection rat model. Sprague-Dawley rats were culled on Day 3 after the ictus, and the vasospastic basilar artery was harvested for isometric investigations of the vessel tone. Ring segments were preincubated with and without L-NAME and/or losartan. RESULTS: Preincubation with L-NAME induced dose-dependent vasoconstriction via endothelin-1 in the non-SAH cohort, which was dose-dependently reduced by losartan. After SAH and dose-dependent endothelin-1 administration, maximal contraction was achieved in the control group without losartan. Furthermore, this maximal contraction was significantly decreased in the losartan group and was reversed by L-NAME. CONCLUSIONS: After SAH, losartan was shown to positively influence the ET(B1) receptor pathway in a non-competitive direct agonistic and indirect fashion. Losartan alleviated the maximum contraction triggered by endothelin-1. This effect was resolved due to NO inhibition by L-NAME. Considering this spasmolytic effect of losartan besides its already well-known effects (attenuating cerebral inflammation, restoring cerebral autoregulation and reducing epileptogenic activity) and alleviating early brain injury, losartan seems to have potential as a promising pharmacological agent after SAH.
Assuntos
Losartan/farmacologia , Hemorragia Subaracnóidea/tratamento farmacológico , Animais , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/metabolismo , Modelos Animais de Doenças , Endotelina-1/metabolismo , Losartan/metabolismo , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor de Endotelina B/metabolismo , Medicina Regenerativa/métodos , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/metabolismo , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Vasodilatadores/metabolismo , Vasodilatadores/farmacologia , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/etiologiaRESUMO
Identifying the metabolites of a drug has become an indispensable task in the development of new drugs. Dipfluzine (Dip) is a promising candidate for the treatment of cerebral vascular diseases and has 5 metabolites (M1â¼M5) in rat urine and liver microsomes, but their biological activity is still unknown. Because selective cerebral vasodilation is a main role of Dip, we investigated the vasodilation of Dip and its 5 metabolites in isolated Sprague-Dawley (SD) male rat basilar arteries preconstricted with high-K+ or 5-HT. The results showed that only M1 possessed concentration-dependent inhibitory activity on the vasoconstriction of arteries with or without the endothelium, and M1 has a more potent vasodilatory effect than Dip on both contraction models. Like Dip, the vasodilatory mechanisms of M1 may be not only related to receptor-operated and voltage-dependent calcium ion channels of smooth muscle cells but also to the release of NO and EDHF from endothelial cells and the opening of Ca2+-activated K+ channels and ATP-sensitive potassium ion channels. Unlike Dip, the vasodilation mechanism of M1 is also related to the opening of voltage-sensitive K+ channel. Together with more selectivity to non-VDCC than Dip, this may partially explain why M1 has stronger vasodilatory effects than Dip. The mechanisms of vasodilation of Dip and M1 may result from the combined action of these or other factors, especially blocking non-endothelium dependent non-VDCC and endothelium dependent IKCa channels. These results point to the possibility that M1 provides synergism for the clinical use of Dip, which may inform the synthesis of new drugs.
Assuntos
Artéria Basilar/efeitos dos fármacos , Cinarizina/análogos & derivados , Vasodilatadores/farmacologia , Animais , Artéria Basilar/fisiologia , Cinarizina/farmacologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Técnicas In Vitro , Masculino , Canais de Potássio/fisiologia , Ratos Sprague-Dawley , Vasodilatação/efeitos dos fármacosRESUMO
Subarachnoid hemorrhage (SAH) frequently results in several serious complications, such as cerebral vasospasm. We previously reported the effect of trehalose on vasospasm, inflammatory responses, and lipid peroxidation induced by blood exposure. Herein, to further elucidate the mechanism of action of trehalose, we investigated whether or not post-administration of trehalose can directly influence blood clotting in the cistern. As a result of trehalose injection after the onset of experimental SAH, blood clotting around the basilar artery was clearly inhibited. We also found that trehalose positively impacted coagulation and fibrinolysis parameters in rat, rabbit and human plasma in vitro. These findings suggest that trehalose has suppressive effects on blood clotting in addition to vasospasm, inflammatory responses, and lipid peroxidation after SAH.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Hemorragia Subaracnóidea/complicações , Trealose/farmacologia , Animais , Artéria Basilar/efeitos dos fármacos , Modelos Animais de Doenças , Fibrinólise/efeitos dos fármacos , Humanos , Masculino , Coelhos , Ratos Sprague-Dawley , Hemorragia Subaracnóidea/sangue , Hemorragia Subaracnóidea/tratamento farmacológicoRESUMO
AIM: To investigate the effects of an anti-ischemic agent, mildronate, on subarachnoid hemorrhage-induced vasospasm. MATERIAL AND METHODS: Rabbits were randomly divided into four groups: control, subarachnoid hemorrhage (SAH), vehicle, and mildronate (n=8 animals per group). In the treatment group, 200 mg/kg of mildronate were intraperitoneally administered 5 minutes after the procedure and continued for 3 days as daily administrations of the same dose. At the end of the third day, the cerebrum, cerebellum, and brain stem were perfused, fixated, and removed for histopathological examination. Tissues were examined for arterial wall thickness, luminal area, and hippocampal neuronal degeneration. RESULTS: Mildronate group showed significantly increased luminal area and reduced wall thickness of the basilar artery compared with the subarachnoid hemorrhage group. In addition, the hippocampal cell degeneration score was significantly lower in the mildronate group than in the SAH and vehicle groups. CONCLUSION: These results show that mildronate exerts protective effects against SAH-induced vasospasm and secondary neural injury.
Assuntos
Metilidrazinas/farmacologia , Hemorragia Subaracnóidea , Vasoespasmo Intracraniano , Animais , Artéria Basilar/efeitos dos fármacos , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Masculino , Fármacos Neuroprotetores/farmacologia , Coelhos , Vasodilatadores/farmacologia , Vasoespasmo Intracraniano/etiologiaRESUMO
Nicotinic acetylcholine receptor activation on the perivascular sympathetic nerves via axo-axonal interaction mechanism causes norepinephrine release, which triggers the neurogenic nitrergic relaxation in basilar arteries to meet the need of a brain. Donepezil and huperzine A, which are the cholinesterase inhibitors used for Alzheimer's disease therapy, exert controversial effects on nicotinic acetylcholine receptors. Therefore, we investigated how donepezil and huperzine A via the axo-axonal interaction regulate the neurogenic vasodilation of isolated porcine basilar arteries and define their action on different subtypes of the nicotinic acetylcholine receptor by using blood vessel myography, calcium imaging, and electrophysiological techniques. Both nicotine (100 µM) and transmural nerve stimulation (TNS, 8 Hz) induce NO-mediated dilation in the arteries. Nicotine-induced vasodilations were concentration-dependently inhibited by huperzine A and donepezil, with the former being 30 fold less potent than the latter. Both cholinesterase inhibitors weakly and equally decreased TNS-elicited nitrergic vasodilations. Neither huperzine A nor donepezil affected isoproterenol (a ß adrenoceptor-agonist)- or sodium nitroprusside (a NO donor)-induced vasodilation. Further, huperzine A was less potent than donepezil in inhibiting nicotine-elicited calcium influxes in rodent superior cervical ganglionic neurons and inward currents in α7- and α3ß2-nicotinic acetylcholine receptor-expressing Xenopus oocytes. In conclusion, huperzine A may exert less harmful effect over donepezil on maintaining brainstem circulation and on the nicotinic acetylcholine receptor-associated cognition deficits during treatment for Alzheimer's disease.
Assuntos
Artéria Basilar/fisiopatologia , Inibidores da Colinesterase/efeitos adversos , Disfunção Cognitiva/induzido quimicamente , Neurônios Nitrérgicos/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Alcaloides/administração & dosagem , Alcaloides/efeitos adversos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/fisiopatologia , Animais , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/inervação , Tronco Encefálico/irrigação sanguínea , Tronco Encefálico/efeitos dos fármacos , Tronco Encefálico/patologia , Tronco Encefálico/fisiopatologia , Cálcio/metabolismo , Inibidores da Colinesterase/administração & dosagem , Disfunção Cognitiva/fisiopatologia , Donepezila/administração & dosagem , Donepezila/efeitos adversos , Relação Dose-Resposta a Droga , Humanos , Modelos Animais , Nicotina/metabolismo , Neurônios Nitrérgicos/metabolismo , Neurônios Nitrérgicos/fisiologia , Oócitos , Técnicas de Patch-Clamp , Ratos , Receptores Nicotínicos/metabolismo , Sesquiterpenos/administração & dosagem , Sesquiterpenos/efeitos adversos , Suínos , Transmissão Sináptica/efeitos dos fármacos , Vasodilatação/fisiologia , Xenopus laevisRESUMO
OBJECTIVE: To investigate the role of inflammatory response, oxidative damage and changes of ATP-sensitive potassium channels (sKATP) in basilar artery (BA) smooth muscle cells (SMCS) of rabbits in subarachnoid hemorrhage (SAH) model. METHODS: Time course studies on inflammatory response by real-time PCR, oxidative process and function of isolated basilar artery after SAH in New Zealand White rabbits were performed. Basilar artery smooth muscle cells (BASMCs) in each group were obtained and whole-cell patch-clamp technique was applied to record cell membrane capacitance and KATP currents. The morphologies of basal arteries were analyzed. Protective effect of shikonin were also determine by same parameters. RESULTS: Inflammatory cytokines levels were highest at 24h compare to 72h after SAH whereas the oxidative damage and cell death marker were at highest peak at 72h. Oxidative damage peak coincided with significant alterations in cell membrane capacitance, KATP currents and morphological changes in basilar arteries. Shikokin pretreatment attenuated early inflammatory response at 24h and associated oxidative damage at 72h. Finally, shikonin attenuated morphological changes in basilar arteries and dysfunction. CONCLUSION: Currents of ATP-sensitive potassium channels in basilar smooth muscle cells decreased after SAH by putative oxidative modification from immediate inflammatory response and can be protected by shikonin pretreatment.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Artéria Basilar/efeitos dos fármacos , Canais KATP/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Naftoquinonas/farmacologia , Hemorragia Subaracnóidea/patologia , Animais , Artéria Basilar/metabolismo , Artéria Basilar/patologia , Citocinas/metabolismo , Feminino , Mediadores da Inflamação/metabolismo , Masculino , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Estresse Oxidativo , Técnicas de Patch-Clamp , Coelhos , Hemorragia Subaracnóidea/imunologia , Hemorragia Subaracnóidea/metabolismoRESUMO
The neuroprotective and vasodilatory effects of cinnamaldehyde have been widely studied and documented. On the basis of these findings, we hypothesized that cinnamaldehyde exhibits therapeutic effects on subarachnoid hemorrhage-induced early brain injury and cerebral vasospasm. Thirty-two adult male New Zealand white rabbits were randomly divided into four groups of eight rabbits: control, subarachnoid hemorrhage, subarachnoid hemorrhage + vehicle, and subarachnoid hemorrhage + cinnamaldehyde. An intraperitoneal dose of 50 mg/kg cinnamaldehyde was administered 5 min following an intracisternal blood injection, followed by three further daily injections at identical doses. The animals were sacrificed 72 h after subarachnoid hemorrhage was induced. The cross-sectional areas and arterial wall thicknesses of the basilar artery were measured and hippocampal degeneration scores were evaluated. Treatment with cinnamaldehyde was effective in providing neuroprotection and attenuating cerebral vasospasm after subarachnoid hemorrhage in rabbits. It effectively increased the cross-sectional areas of the basilar artery and reduced the arterial wall thickness; in addition, hippocampal degeneration scores were lower in the cinnamaldehyde group. The findings of this study showed, for the first time to our knowledge, that cinnamaldehyde exhibits neuroprotective activity against subarachnoid hemorrhage-induced early brain injury and that it can prevent vasospasm. Potential mechanisms underlying the neuroprotection and vasodilation were discussed. Cinnamaldehyde could play a role in subarachnoid hemorrhage treatment.
Assuntos
Acroleína/análogos & derivados , Degeneração Neural/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Hemorragia Subaracnóidea/tratamento farmacológico , Vasoespasmo Intracraniano/tratamento farmacológico , Acroleína/farmacologia , Acroleína/uso terapêutico , Animais , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/patologia , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Masculino , Degeneração Neural/patologia , Fármacos Neuroprotetores/farmacologia , Coelhos , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/patologia , Vasoespasmo Intracraniano/etiologia , Vasoespasmo Intracraniano/patologiaRESUMO
Background: Aneurysmal subarachnoid haemorrhage (SAH) is a variant of haemorrhagic stroke with a striking 50% mortality rate. In addition to the initial insult, secondary delayed brain injury may occur days after the initial ischemic insult and is associated with vasospasms leading to delayed cerebral ischemia. We have previously shown that the MEK1/2 inhibitor U0126 improves neurological assessment after SAH in rats. Aim: The purpose of the present study was to analyse the impact of a broad selection of high potency MEK1/2 inhibitors in an organ culture model and use the IC50 values obtained from the organ culture to select highly potent inhibitors for pre-clinical in vivo studies. Results: Nine highly potent mitogen activated protein kinase kinase (MEK1/2) inhibitors were screened and the two most potent inhibitors from the organ culture screening, trametinib and PD0325901, were tested in an in vivo experimental rat SAH model with intrathecal injections. Subsequently, the successful inhibitor trametinib was administered intraperitoneally in a second in vivo study. In both regimens, trametinib treatment caused significant reductions in the endothelin-1 induced contractility after SAH, which is believed to be associated with endothelin B receptor up-regulation. Trametinib treated rats showed improved neurological scores, evaluated by the ability to traverse a rotating pole, after induced SAH. Conclusion: The PD0325901 treatment did not improve the neurological score after SAH, nor showed any beneficial therapeutic effect on the contractility, contrasting with the reduction in neurological deficits seen after trametinib treatment. These data show that trametinib might be a potential candidate for treatment of SAH.
Assuntos
Artérias Cerebrais/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Hemorragia Subaracnóidea/tratamento farmacológico , Animais , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/metabolismo , Benzamidas/farmacologia , Benzamidas/uso terapêutico , Artérias Cerebrais/metabolismo , Difenilamina/análogos & derivados , Difenilamina/farmacologia , Difenilamina/uso terapêutico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Masculino , Contração Muscular/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Piridonas/farmacologia , Piridonas/uso terapêutico , Pirimidinonas/farmacologia , Pirimidinonas/uso terapêutico , Ratos , Ratos Sprague-DawleyRESUMO
Although cerebral vascular smooth muscle cell (VSMC) phenotypic switching is involved in the vascular dysfunction after subarachnoid haemorrhage (SAH), the precise mechanisms are still unclear. High mobility group box-1 (HMGB1) has been identified as a modulator in VSMC proliferation. The purpose of this study was to investigate the potential role of HMGB1 in the VSMC phenotypic switching following SAH. An endovascular perforation SAH model was used in our experiments. The expression levels of HMGB1, α-smooth muscle actin (α-SMA), osteopontin (OPN), smooth muscle myosin heavy chain (SM-MHC), embryonic smooth muscle myosin heavy chain (Smemb), TXA2, PAR-1 and AT1 receptor were evaluated by Western blot analyses. Iba1-positive cells and apoptotic cells were determined by immunofluorescence staining and TUNEL staining, respectively. Vasoconstriction of the isolated basilar artery was stimulated by thrombin and KCl. We found that HMGB1 expression was markedly increased following SAH, and anti-HMGB1 mAb significantly reversed VSMC phenotypic switching and vascular remodelling in rats. However, the effects of HMGB1 on VSMC phenotypic switching were partly blocked in the presence of SC79, a potent activator of phosphatidylinositol-3-kinase-AKT (PI3K/AKT). Furthermore, the enhanced vasoconstriction and decreased cerebral cortical blood flow induced by SAH were reversed by anti-HMGB1 mAb. Finally, we found that anti-HMGB1 mAb attenuated microglial activation and brain oedema, ameliorating neurological dysfunction. These results indicated that HMGB1 is a useful regulator of VSMC phenotypic switching and vascular remodelling following SAH and might be exploited as a novel therapeutic target for delayed cerebral ischaemia.
Assuntos
Anticorpos Monoclonais/farmacologia , Proteína HMGB1/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Hemorragia Subaracnóidea/patologia , Animais , Artéria Basilar/efeitos dos fármacos , Artéria Basilar/patologia , Artéria Basilar/fisiologia , Edema Encefálico/patologia , Células Cultivadas , Proteína HMGB1/imunologia , Masculino , Microglia/metabolismo , Microglia/patologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/fisiologia , Fenótipo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais , Remodelação Vascular , VasoconstriçãoRESUMO
Cerebral vasospasm is one of the deleterious complications after subarachnoid hemorrhage (SAH), leading to delayed cerebral ischemia and permanent neurological deficits or even death. Free radicals and oxidative stress are considered as crucial causes contributing to cerebral vasospasm and brain damage after SAH. Tetramethylpyrazine nitrone (TBN), a derivative of the clinically used anti-stroke drug tetramethylpyrazine armed with a powerful free radical scavenging nitrone moiety, has been reported to prevent brain damage from ischemic stroke. The present study aimed to investigate the effects of TBN on vasospasm and brain damage after SAH. Two experimental SAH models were used, a rat model by endovascular perforation and a rabbit model by intracisternal injection of autologous blood. The effects of TBN on SAH were evaluated assessing basilar artery spasm, neuronal apoptosis, and neurological deficits. TBN treatment significantly attenuated vasospasm, improved neurological behavior functions and reduced the number of apoptotic neurons in both the SAH rats and rabbits. Mechanistically, TBN suppressed the increase in 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine immuno-positive cells in the cortex of SAH rat brain. Western blot analyses indicated that TBN effectively reversed the altered expression of Bcl-2, Bax and cytochrome C, and up-regulated nuclear factor erythroid-derived 2-like 2 (Nrf2) and hemeoxygenase-1 (HO-1) protein expressions. In the in vitro studies, TBN inhibited H2O2-induced bEnd.3 cell apoptosis and reduced ROS generation. Additionally, TBN alleviated the contraction of rat basilar artery rings induced by H2O2 ex vivo. In conclusion, TBN ameliorated SAH-induced cerebral vasospasm and neuronal damage. These effects of TBN may be attributed to its anti-oxidative stress effect and up-regulation of Nrf2/HO-1.