scholarly journals Endotoxin Decreases the Contractile Responses of the Porcine Basilar Artery to Vasoactive Substances

1993 ◽  
Vol 13 (4) ◽  
pp. 712-719 ◽  
Author(s):  
Masami Ueno ◽  
Tony J.-F. Lee
Keyword(s):  
Endothelial Cells ◽  
Basilar Artery ◽  
Muscle Tone ◽  
Cerebral Arteries ◽  
Contractile Responses ◽  
Vasoactive Substances ◽  
Basilar Arteries ◽  
Arterial Reactivity ◽  
Lps Treatment

The effects of endotoxin (lipopolysaccharide; LPS) on the reactivity of isolated porcine basilar artery were examined using in vitro tissue bath techniques. The active muscle tone of the basilar arterial rings with or without endothelial cells induced by U46619 (1 μ M) reached a plateau in 15 min, which was stable for the first hour and gradually decreased during the next 5 h. This time-dependent decrease in tone was significantly potentiated in the presence of LPS (20 μg/ml). The potentiation by LPS was blocked by Nw-nitro-l-arginine (l-NNA; 60 μ M), methylene blue (10 μ M), and dexamethasone (1 μ M) but not by hemoglobin (1 μ M). The effect of l-NNA was readily reversed by l-arginine but not by d-arginine. Furthermore, the contractile responses of porcine basilar arterial rings with or without intact endothelium to U46619 and KCl were decreased following incubation with LPS (20 μg/ml) for 4 h. Similar hyporeactivity was observed in cold storage–denervated cerebral arteries incubated with LPS for 4 h. This decrease in contractile responses in LPS-treated rings was reversed by 60 μ M l-NNA and 1 μ M dexamethasone. These results indicate that LPS treatment renders the porcine basilar arteries hyporesponsive to vasoconstrictors. Since effects of LPS were not modified by the presence of endothelial cells and perivascular neurons, the alteration in cerebral arterial reactivity may be due in part to an enhanced formation of nitric oxide from l-arginine in the vascular smooth muscle cells.

Cerebral vasospasm: contractile activity of hemoglobin in isolated canine basilar arteries

1980 ◽  
Vol 53 (6) ◽  
pp. 787-793 ◽  
Author(s):  
Takeo Tanishima
Keyword(s):  
Cerebral Vasospasm ◽  
Basilar Artery ◽  
Contractile Activity ◽  
Cerebral Arteries ◽  
Adenosine Monophosphate ◽  
Active Species ◽  
Exchange Chromatography ◽  
Basilar Arteries ◽  
Chronic Cerebral Vasospasm

✓ Recent studies suggest the possible role of the red blood cell (RBC) in causing chronic cerebral vasospasm. However, the basic action of hemoglobin (Hb), the major component of the RBC, on cerebral arteries remains unknown. The present study was undertaken to analyze the contractile effects of human Hb (purified by ion-exchange chromatography) on canine arteries in vitro. The contractile activity of lysed RBC was shown to be derived from Hb. Hemoglobin in oxygenated form (oxyHb) caused a maximum contraction equal to about 70% of that induced by serotonin in the basilar artery. Ferrous Hb's (oxyHb and carboxyHb) produced much greater contraction than ferric Hb's (methemoglobin and cyanmethemoglobin), suggesting that superoxide radicals, an active species of oxygen, may be related to the contractile activity of Hb. Neither methysergide, phentolamine, mepyramine, nor aspirin inhibited the vasoconstrictive activity of oxyHb. This finding indicates that the activation of serotonergic, alpha-adrenergic, or histaminergic H1 receptors, or prostaglandin synthesis may not be involved in the mechanism of action of oxyHb. The constituents of Hb caused little or no contraction as compared with Hb as a whole. The basilar artery was more highly sensitive to Hb than arteries from other anatomical locations. Cyclic adenosine monophosphate caused a very slight decrease in the Hb-induced contraction. It is concluded that oxyHb can contract cerebral arteries in vitro. These results, coupled with recent reports on the participation of the RBC in producing chronic vasospasm, strongly suggest that oxyHb released from RBC's plays an important role in the pathogenesis of chronic cerebral vasospasm.

scholarly journals Preclinical evaluation of Millipede 088 intracranial aspiration catheter in cadaver and in vitro thrombectomy models

2020 ◽  
pp. neurintsurg-2020-016218 ◽  
Author(s):  
Seán Fitzgerald ◽  
David Ryan ◽  
John Thornton ◽  
Raul G Nogueira
Keyword(s):  
Basilar Artery ◽  
Blood Clot ◽  
Cerebral Arteries ◽  
In Vitro Study ◽  
Cadaveric Study ◽  
Vitro Study ◽  
First Pass ◽  
Fresh Frozen ◽  
Basilar Arteries

BackgroundLarger bore aspiration catheters are expected to significantly improve the speed and completeness of acute stroke revascularization.ObjectiveTo evaluate the navigability and clot retrieval performance of a novel 8Fr aspiration catheter, Millipede 088 (Perfuze Ltd), using fresh-frozen cadavers and an in vitro thrombectomy model, respectively.MethodsCadaveric study: Transfemoral catheterization of the intracranial arteries was performed in six cadavers, allowing evaluation of navigation to 12 middle cerebral arteries (MCAs) and six basilar arteries. Commercially available 6Fr aspiration catheters (SOFIA Plus, Microvention) were used as controls. In vitro study: Three human blood clot phenotypes were created; red blood cell-rich, mixed, and fibrin/platelets-rich. Two clot sizes, resulting in occlusion of the internal carotid artery (ICA) and MCA-M1 were investigated. Endpoints were first-pass effect (FPE), first-pass complete ingestion, and second-pass recanalization.ResultsCadaveric study: Both the Millipede 088 and SOFIA Plus devices reached the distal MCA-M1 and the basilar artery in 10/12 and 2/2 of the navigation attempts, respectively. In the two instances of unsuccessful navigation, neither device was able to cross the ophthalmic artery. In vitro study: In 10 mm long M1 occlusions, Millipede 088 achieved 100% FPE versus 40% for 6Fr devices (p>0.001). In 20 mm long ICA occlusions, Millipede 088 achieved 100% removal success within two passes in each clot phenotype compared with an average of 27% for 6Fr devices (p>0.001).ConclusionsNavigation of the Millipede 088 catheter to the MCA-M1 and basilar artery is feasible in a cadaver model. Millipede 088 demonstrates superiority over 6Fr aspiration catheters for three representative clot phenotypes at the most common sites of occlusion in an in vitro vasculature model.

scholarly journals Contractile and Endothelium-Dependent Dilatory Responses of Cerebral Arteries at Various Extracellular Magnesium Concentrations

1991 ◽  
Vol 11 (1) ◽  
pp. 161-164 ◽  
Author(s):  
Mária Faragó ◽  
Csaba Szabó ◽  
Eörs Dóra ◽  
Ildikó Horváth ◽  
Arisztid G. B. Kovách
Keyword(s):  
Smooth Muscle ◽  
Vascular Reactivity ◽  
Calcium Influx ◽  
Cerebral Arteries ◽  
Inhibitory Effect ◽  
Contractile Responses ◽  
Middle Cerebral Arteries ◽  
The Right ◽  
Endothelial Receptor

To clarify the effect of extracellular magnesium (Mg2+) on the vascular reactivity of feline isolated middle cerebral arteries, the effects of slight alterations in the Mg2+ concentration on the contractile and endothelium-dependent dilatory responses were investigated in vitro. The contractions, induced by 10−8-10−5 M norepinephrine, were significantly potentiated at low Mg2+ (0.8 m M v. the normal, 1.2 m M). High (1.6 and 2.0 m M) Mg2+ exhibited an inhibitory effect on the contractile responses. No significant changes, however, in the EC50 values for norepinephrine were found. The endothelium-dependent relaxations induced by 108–10−5 M acetylcholine were inhibited by high (1.6 and 2.0 m M) Mg2+. Lowering of the Mg2+ concentration to 0.8 m M or total withdrawal of this ion from the medium failed to alter the dilatory potency of acetylcholine. The changes in the dilatory responses also shifted the EC50 values for acetylcholine to the right. The present results show that the contractile responses of the cerebral arteries are extremely susceptible to the changes of Mg2+ concentrations. In response to contractile and endothelium-dependent dilatory agonists, Mg2+ probably affects both the calcium influx into the endothelial and smooth muscle cells as well as the binding of acetylcholine to its endothelial receptor. Since Mg2+ deficiency might facilitate the contractile but not the endothelium-dependent relaxant responses, the present study supports a role for Mg2+ deficiency in the development of the cerebral vasospasm.

scholarly journals Mechanism of the Enhanced Vasoconstrictor Responses to Endothelin-1 in Canine Cerebral Arteries

1991 ◽  
Vol 11 (3) ◽  
pp. 371-379 ◽  
Author(s):  
Chiharu Tanoi ◽  
Yoshio Suzuki ◽  
Masato Shibuya ◽  
Kenichiro Sugita ◽  
Kaoru Masuzawa ◽  
...  
Keyword(s):  
Basilar Artery ◽  
Resting State ◽  
Mesenteric Artery ◽  
Cerebral Arteries ◽  
Mesenteric Arteries ◽  
Free Solution ◽  
Contractile Responses ◽  
Endothelin 1 ◽  
Voltage Dependent ◽  
Small Contraction

Vasoconstrictor effects of endothelin-1 (ET) were investigated in endothelium-denuded strips of cerebral (basilar and posterior cerebral) and mesenteric arteries of the dog. ET produced a concentration-dependent contraction in these arteries. Contractile responses to lower concentrations (below 3 × 10−10 M) of ET were significantly greater in the cerebral arteries than in the mesenteric artery. Inhibition by nifedipine of the contractile responses to ET was greater in the basilar artery than in the mesenteric artery. After the inhibition by 10−7 M nifedipine, the remaining responses to ET were similar in the two arteries. Cerebral arteries, but not the mesenteric artery, relaxed significantly from the resting level when placed in a Ca2+ -free solution containing 0.1 m M EGTA (0-Ca solution). Readdition of Ca2+ to the cerebral arteries placed in the 0-Ca solution caused a biphasic contraction that was sensitive to nifedipine. When 10−9 M ET was introduced before the Ca2+-induced contraction, this peptide produced only a very small contraction, but enhanced the Ca2+-induced contraction. The extent of the enhancement induced by ET was much greater in the cerebral arteries than in the mesenteric artery. These results indicate that the enhanced responses to ET in the cerebral arteries were dependent to a large extent on Ca2+ influx through voltage-dependent Ca2+ channels (VDCs). It is likely that the VDCs in these arteries are more activated in the resting state than those in the mesenteric artery.

scholarly journals in vitro Effects of Calcium Antagonists PN 200-110, Nifedipine, and Nimodipine on Human and Canine Cerebral Arteries

1983 ◽  
Vol 3 (3) ◽  
pp. 354-361 ◽  
Author(s):  
E. Müller-Schweinitzer ◽  
P. Neumann
Keyword(s):  
Rank Order ◽  
Cerebral Arteries ◽  
Isometric Tension ◽  
Mesenteric Arteries ◽  
Organ Bath ◽  
Vasoconstrictor Response ◽  
Dihydropyridine Derivative ◽  
Basilar Arteries ◽  
In Vitro Effects

PN 200–110 [4-(2, 1, 3-benzoxadiazol - 4 -) - 1,4-dihydro - 2,6 - dimethyl - pyridine - 3,5 - dicarboxylic acid methyl 1-methylethyl ester], a new dihydropyridine derivative, was investigated by recording isometric tension on spiral strips from human and canine arteries in tissue baths at 37°C. Responses to increasing concentrations of CaCl2 were investigated in calcium-free depolarizing solution (60 mmol/L KCl in equimolar replacement for NaCl, 50 mmol/L TRIZMA buffer, pH 7.4). Comparison of those concentrations that reduced the vasoconstrictor response to 1.6 mmol/L CaCl2 by 50% revealed the following order of potencies on both human and canine arteries: PN 200–110 > nimodipine > nifedipine. Responses to 5-hydroxytryptamine (5-HT) and blood were investigated in Krebs–Henseleit solution (NaHCO3 buffer). On canine arteries, PN 200–110 antagonized responses to 5-HT when used at 10–30 pmol/L; it was ∼70 times more potent on basilar than on mesenteric arteries, whereas both nifedipine and nimodipine were, respectively, ∼10 and 6 times more potent on basilar than on mesenteric arteries. When canine basilar arteries were constricted by the addition of blood to the organ bath, each of the investigated dihydropyridine derivatives elicited concentration-dependent relaxation, producing the following order of potencies: PN 200–110 > nifedipine = nimodipine. On human anterior cerebral arteries, the blood-induced contractions were counteracted in the following rank order: PN 200–110 = nimodipine > nifedipine. The results suggest that due to its potent calcium-blocking activity on cerebral arteries, PN 200–110 might be of value for the prevention and treatment of cerebrovascular spasms following subarachnoid hemorrhage.

scholarly journals Cerebrovascular responses in mice deficient in the potassium channel, TREK-1

2010 ◽  
Vol 299 (2) ◽  
pp. R461-R469 ◽  
Author(s):  
Khodadad Namiranian ◽  
Eric E. Lloyd ◽  
Randy F. Crossland ◽  
Sean P. Marrelli ◽  
George E. Taffet ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Linolenic Acid ◽  
Basilar Artery ◽  
Cerebral Arteries ◽  
K Channel ◽  
Whole Cell ◽  
Middle Cerebral Arteries ◽  
Basilar Arteries ◽  
Cerebrovascular Smooth Muscle Cells ◽  
Pore Domain

We tested the hypothesis that TREK-1, a two-pore domain K channel, is involved with dilations in arteries. Because there are no selective activators or inhibitors of TREK-1, we generated a mouse line deficient in TREK-1. Endothelium-mediated dilations were not different in arteries from wild-type (WT) and TREK-1 knockout (KO) mice. This includes dilations of the middle cerebral artery to ATP, dilations of the basilar artery to ACh, and relaxations of the aorta to carbachol, a cholinergic agonist. The nitric oxide (NO) and endothelium-dependent hyperpolarizing factor components of ATP dilations were identical in the middle cerebral arteries of WT and TREK-1 KO mice. Furthermore, the NO and cyclooxygenase-dependent components were identical in the basilar arteries of the different genotypes. Dilations of the basilar artery to α-linolenic acid, an activator of TREK-1, were not affected by the absence of TREK-1. Whole cell currents recorded using patch-clamp techniques were similar in cerebrovascular smooth muscle cells (CVSMCs) from WT and TREK-1 KO mice. α-linolenic acid or arachidonic acid increased whole cell currents in CVSMCs from both WT and TREK-1 KO mice. The selective blockers of large-conductance Ca-activated K channels, penitrem A and iberiotoxin, blocked the increased currents elicited by either α-linolenic or arachidonic acid. In summary, dilations were similar in arteries from WT and TREK-1 KO mice. There was no sign of TREK-1-like currents in CVSMCs from WT mice, and there were no major differences in currents between the genotypes. We conclude that regulation of arterial diameter is not altered in mice lacking TREK-1.

scholarly journals Microparticle-mediated VZV propagation and endothelial activation

Neurology ◽  
2019 ◽  
Vol 94 (5) ◽  
pp. e474-e480 ◽  
Author(s):  
Despina Eleftheriou ◽  
Elena Moraitis ◽  
Ying Hong ◽  
Mark Turmaine ◽  
Cristina Venturini ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Remodeling ◽  
In Vitro Model ◽  
Cerebral Arteries ◽  
Virus Transmission ◽  
Endothelial Activation ◽  
Arterial Ischemic Stroke ◽  
Varicella Zoster ◽  
Vitro Model

ObjectiveVaricella zoster virus (VZV) can spread anterogradely and infect cerebral arteries causing VZV vasculopathy and arterial ischemic stroke. In this study, we tested the hypothesis that virus-infected cerebrovascular fibroblasts undergo phenotypic changes that promote vascular remodeling and facilitate virus transmission in an in vitro model of VZV vasculopathy. The aims of this project were therefore to examine the changes that virus-infected human brain adventitial vascular fibroblasts (HBVAFs) undergo in an in vitro model of VZV vasculopathy and to identify disease biomarkers relating to VZV-related vasculopathy.MethodsHBVAFs were infected with VZV, and their ability to migrate, proliferate, transdifferentiate, and interact with endothelial cells was studied with flow cytometry. Microparticles (MPs) released from these cells were isolated and imaged with transmission electron microscopy, and their protein content was analyzed with mass spectrometry. Circulating MP profiles were also studied in children with VZV and non-VZV vasculopathy and compared with controls.ResultsVZV-infected HBVAFs transdifferentiated into myofibroblasts with enhanced proliferative and migratory capacity. Interaction of VZV-infected HBVAFs with endothelial cells resulted in endothelial dysfunction. These effects were, in part, mediated by the release of MPs from VZV-infected HBVAFs. These MPs contained VZV virions that could transmit VZV to neighboring cells, highlighting a novel model of VZV cell-to-cell viral dissemination. MPs positive for VZV were significantly higher in children with VZV-related vasculopathy compared to children with non-VZV vasculopathy (p = 0.01) and controls (p = 0.007).ConclusionsVZV-infected HBVAFs promote vascular remodeling and facilitate virus transmission. These effects were mediated by the release of apoptotic MPs that could transmit VZV infection to neighboring cells through a Trojan horse means of productive viral infection. VZV+ MPs may represent a disease biomarker worthy of further study.

Neurogenically evoked cerebral artery constriction is mediated by neuropeptide Y

1994 ◽  
Vol 72 (9) ◽  
pp. 1086-1088 ◽  
Author(s):  
Ismail Laher ◽  
Peter Germann ◽  
John A. Bevan
Keyword(s):  
Neuropeptide Y ◽  
Cerebral Artery ◽  
Basilar Artery ◽  
Cerebral Arteries ◽  
Immune Serum ◽  
Nerve Endings ◽  
Transmural Stimulation ◽  
Basilar Arteries ◽  
Neurogenic Vasoconstriction ◽  
Stimulation Of

We examined the proposal that neuropeptide Y (NPY) released from nerve endings constricts cerebral arteries. Neurogenic vasoconstriction of rabbit basilar arteries is of adrenergic origin but is resistant to blockade by classical α-adrenoceptor antagonists. Tetrodotoxin-sensitive contractions of the rabbit basilar artery were elicited by transmural stimulation of nerves. The contractions were inhibited by incubation of tissues with an antiserum to NPY (0.32 μL undiluted immune serum/mL); addition of prazosin (0.1 μM) did not further attenuate the nerve-mediated contraction. The antiserum to NPY also antagonized vasoconstriction due to exogenously administered NPY and was without effect on responses due to histamine or angiotensin. Our results indicate that neurogenic vasoconstriction of the rabbit basilar artery is largely due to the release of NPY and that it is unlikely that other vasoconstrictors contribute significantly to the increased tone.Key words: cerebral artery, nerves, neuropeptide Y, norepinephrine.

Dose responses of cerebral arteries of the dog, rabbit, and man to human hemoglobin in vitro

1980 ◽  
Vol 53 (4) ◽  
pp. 486-490 ◽  
Author(s):  
Glyn R. Wellum ◽  
Thomas W. Irvine ◽  
Nicholas T. Zervas
Keyword(s):  
Cerebral Arteries ◽  
Postmortem Changes ◽  
Human Hemoglobin ◽  
Content Type ◽  
Weak Response ◽  
Basilar Arteries ◽  
Human Arteries ◽  
Dose Responses ◽  
Fine Print

✓ Dose responses in vitro of the basilar arteries of the dog, rabbit, and man to human hemoglobin are reported. For each species, the response occurred over a range of 10−9M to greater than 10−5M hemoglobin. When compared to a maximum serotonin contraction, the relative constriction induced by 10−5M hemoglobin was greater in the rabbit than in the dog, which in turn was greater than in man. The comparatively weak response of the human arteries is probably attributable to postmortem changes.

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