Mechanisms of Action of Endothelin on Isolated Feline Cerebral Arteries: In vitro Pharmacology and Electrophysiology

Vascular endothelium has been found to produce a strong and potent vasoconstrictor peptide, endothelin. In this study, we have examined basic mechanisms underlying the contractile response of cerebral vessels to endothelin using in vitro pharmacology and electrophysiology. It was found that endothelin produced strong concentration-dependent contractions of circular segments of the feline middle cerebral artery. The response was slow in onset and long lasting. The vessels showed a remarkably strong tachyphylactic reaction upon repeated exposure to endothelin. The contractile effect of endothelin was not modified by the α-adrenoceptor antagonist phen-tolamine (10−6 M) or the 5-hydroxytryptamine antagonist ketanserin (10−6 M). Mechanical removal of the endothelium decreased potassium contractions while the maximum response to endothelin was only slightly reduced. There was no change in sensitivity of the cerebral artery to endothelin. The addition of a calcium antagonist (10−6 M diltiazem or 3 × 10−8 M nimodipine) or removal of extracellular calcium from the buffer solution did not change the sensitivity of the artery to endothelin but the maximum response to endothelin was reduced by between 40 and 60% by these procedures. The resting membrane potential of the cat middle cerebral artery was –62.8 ± 3.5 mV. There was no significant depolarization in conjunction with cumulative administration of endothelin in concentrations below 1 × 10−9 M. However, bursts of excitatory junction potentials were occasionally seen in response to high concentrations of endothelin (5 × 10−9 M). The findings suggest that the contractile response to endothelin of cat cerebral arteries involved influx of extracellular calcium through voltage-sensitive calcium channels and is in part mediated via a voltage-insensitive mechanism. Further work is necessary to define the intracellular actions of endothelin.

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Mechanisms of contractile response of cerebral artery to externally-applied fresh blood

Journal of Neurosurgery ◽

10.3171/jns.1975.43.1.0037 ◽

1975 ◽

Vol 43 (1) ◽

pp. 37-47 ◽

Cited By ~ 52

Author(s):

Frederick A. Simeone ◽

Philip Vinall

Keyword(s):

Cerebral Artery ◽

Contractile Response ◽

Extracellular Calcium ◽

Cell Membrane Permeability ◽

Fresh Blood ◽

Content Type ◽

Blood Clots ◽

The Moment ◽

Muscle Cell Membrane

✓ The authors report and analyze the in vitro contractions of fresh bovine cerebral artery on exposure to blood. The vessel does not contract significantly until blood clots on its surfaces; the contraction begins at the moment of clotting and is maintained as long as extracellular calcium is available. Comparative studies with vasoconstrictor amines suggest that serotonin, liberated from platelets by the clotting process, is responsible for this contraction and that the adherent clot itself concentrates the serotonin on the surface of the vessel. This contraction persists throughout the “viability” of the in vitro preparation, approximately 10 hours. Serotonin is capable of producing this sustained contraction by increasing smooth muscle cell membrane permeability to extracellular calcium, which in turn activates native actinomycin.

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Adrenergic vasoconstriction of the goat middle cerebral artery

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1978.235.2.h131 ◽

1978 ◽

Vol 235 (2) ◽

pp. H131-H135

Author(s):

M. V. Conde ◽

J. Marin ◽

M. Salaices ◽

E. J. Marco ◽

B. Gomez ◽

...

Keyword(s):

Electrical Stimulation ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Contractile Response ◽

Cerebral Arteries ◽

Sympathetic Ganglia ◽

Alpha Adrenergic Receptors ◽

Norepinephrine Concentration ◽

Before And After ◽

Cervical Sympathetic

The effects of field electrical stimulation on the contractile response of the isolated middle cerebral artery of the goat were evaluated before and after the use of experimental procedures designed to test the adrenergic component involved. Supramaximal stimuli produced frequency-dependent increases in tension. This response was significantly reduced by phentolamine (10(-6) M), tetrodotoxin (3 X 10(-6) M), and bretylium (5 X 10(-5) M), but not by cocaine (10(-6) M). Arterial segments from goats pretreated with reserpine and from goats in which both superior cervical sympathetic ganglia had been removed 12 days prior to the experiment also showed a significant decrease in the contraction elicited by electrical stimulation. The norepinephrine concentration of the arteries of the circle of Willis from control goats was 2.10 microgram per gram of tissue. Reserpine or gangliectomy reduced the catecholamine content to undetectable levels. It is likely that a major part of the contractile response of cerebral arteries to electrical stimulation is due to release of endogenous norepinephrine which in turn activates the alpha-adrenergic receptors.

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Triptan-induced contractile (5-HT1B receptor) responses in human cerebral and coronary arteries: relationship to clinical effect

Clinical Science ◽

10.1042/cs20050016 ◽

2005 ◽

Vol 109 (3) ◽

pp. 335-342 ◽

Cited By ~ 44

Author(s):

Lars Edvinsson ◽

Erik Uddman ◽

Angelica Wackenfors ◽

Anthony Davenport ◽

Jenny Longmore ◽

...

Keyword(s):

Coronary Artery ◽

Coronary Arteries ◽

Cerebral Artery ◽

Rank Order ◽

Cerebral Arteries ◽

Plasma Concentrations ◽

Receptor Expression ◽

In Vitro Pharmacology ◽

Immunohistochemical Techniques

Triptans are agonists at 5-HT1B and 5-HT1D (where 5-HT is 5-hydroxytryptamine; serotonin) receptors and cause vasoconstriction of isolated blood vessels. The aim of the present study was to determine vasoconstrictor potency (EC50) of triptans in human coronary and cerebral arteries and to examine whether there was any relationship with the maximal plasma concentrations (Cmax; nM) of the drugs achieved following oral administration of clinically relevant doses to man using values reported in the literature. We also examined the expression of 5-HT1B receptors in atherosclerotic and normal coronary arteries. The vasocontractile responses to sumatriptan, rizatriptan or eletriptan were characterized by in vitro pharmacology. The ratio of Cmax/EC50 was calculated. 5-HT1B and 5-HT1D receptors were visualized by immunohistochemical techniques in coronary arteries. Sumatriptan, rizatriptan and eletriptan were powerful vasoconstrictors in cerebral artery. The rank order of agonist potency was eletriptan=rizatriptan=sumatriptan. In the coronary artery, the triptans were weaker vasoconstrictors. The rank order of potency was similar. In cerebral artery the ratio of Cmax/EC50 was not significantly different from unity, indicating a relationship between these two parameters. In general for the coronary artery, the ratios were significantly less than unity, indicating no direct relationship. Immunohistochemistry showed expression of 5-HT1B receptors in the medial layer, but did not reveal any obvious difference in 5-HT1B receptor expression between normal and atherosclerotic coronary arteries. The results support the notion that triptans are selective vasoconstrictors of cerebral arteries over coronary arteries and that there is a relationship between vasoconstrictor potency in cerebral arteries and clinically relevant plasma levels.

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Thrombus Imaging Using 3D Printed Middle Cerebral Artery Model and Preclinical Imaging Techniques: Application to Thrombus Targeting and Thrombolytic Studies

Pharmaceutics ◽

10.3390/pharmaceutics12121207 ◽

2020 ◽

Vol 12 (12) ◽

pp. 1207

Author(s):

Andrea Vítečková Wünschová ◽

Adam Novobilský ◽

Jana Hložková ◽

Peter Scheer ◽

Hana Petroková ◽

...

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Imaging Techniques ◽

Barium Sulphate ◽

Flow Conditions ◽

Preclinical Imaging ◽

Blood Clots ◽

3D Printed

Diseases with the highest burden for society such as stroke, myocardial infarction, pulmonary embolism, and others are due to blood clots. Preclinical and clinical techniques to study blood clots are important tools for translational research of new diagnostic and therapeutic modalities that target blood clots. In this study, we employed a three-dimensional (3D) printed middle cerebral artery model to image clots under flow conditions using preclinical imaging techniques including fluorescent whole-body imaging, magnetic resonance imaging (MRI), and computed X-ray microtomography (microCT). Both liposome-based, fibrin-targeted, and non-targeted contrast agents were proven to provide a sufficient signal for clot imaging within the model under flow conditions. The application of the model for clot targeting studies and thrombolytic studies using preclinical imaging techniques is shown here. For the first time, a novel method of thrombus labeling utilizing barium sulphate (Micropaque®) is presented here as an example of successfully employed contrast agents for in vitro experiments evaluating the time-course of thrombolysis and thus the efficacy of a thrombolytic drug, recombinant tissue plasminogen activator (rtPA). Finally, the proof-of-concept of in vivo clot imaging in a middle cerebral artery occlusion (MCAO) rat model using barium sulphate-labelled clots is presented, confirming the great potential of such an approach to make experiments comparable between in vitro and in vivo models, finally leading to a reduction in animals needed.

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DAKS1, a Kunitz Scaffold Peptide from the Venom Gland of Deinagkistrodon acutus Prevents Carotid-Artery and Middle-Cerebral-Artery Thrombosis via Targeting Factor XIa

Pharmaceuticals ◽

10.3390/ph14100966 ◽

2021 ◽

Vol 14 (10) ◽

pp. 966

Author(s):

Zhiping Jia ◽

Yunyang Liu ◽

Xiaoru Ji ◽

Yizheng Zheng ◽

Zhengyang Li ◽

...

Keyword(s):

Carotid Artery ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Inhibitory Activity ◽

Bleeding Risk ◽

Venom Gland ◽

Artery Occlusion ◽

Factor Xia ◽

Deinagkistrodon Acutus

Scaffold-based peptides (SBPs) are fragments of large proteins that are characterized by potent bioactivity, high thermostability, and low immunogenicity. Some SBPs have been approved by the FDA for human use. In the present study, we developed SBPs from the venom gland of Deinagkistrodon acutus (D. acutus) by combining transcriptome sequencing and Pfam annotation. To that end, 10 Kunitz peptides were discovered from the venom gland of D. acutus, and most of which peptides exhibited Factor XIa (FXIa) inhibitory activity. One of those, DAKS1, exhibiting strongest inhibitory activity against FXIa, was further evaluated for its anticoagulant and antithrombotic activity. DAKS1 prolonged twofold APTT at a concentration of 15 μM in vitro. DAKS1 potently inhibited thrombosis in a ferric chloride-induced carotid-artery injury model in mice at a dose of 1.3 mg/kg. Furthermore, DAKS1 prevented stroke in a transient middle cerebral-artery occlusion (tMCAO) model in mice at a dose of 2.6 mg/kg. Additionally, DAKS1 did not show significant bleeding risk at a dose of 6.5 mg/kg. Together, our results indicated that DAKS1 is a promising candidate for drug development for the treatment of thrombosis and stroke disorders.

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Diffusion- and Susceptibility Weighted Imaging Mismatch Correlates With Collateral Circulation and Prognosis After Middle Cerebral Artery M1-Segment Occlusion

Frontiers in Neurology ◽

10.3389/fneur.2021.660529 ◽

2021 ◽

Vol 12 ◽

Author(s):

Zhihua Xu ◽

Zhenhua Tong ◽

Yang Duan ◽

Dengxiang Xing ◽

Hongyan Song ◽

...

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Collateral Circulation ◽

Cerebral Arteries ◽

Binary Logistic Regression ◽

National Institutes Of Health ◽

Susceptibility Weighted Imaging ◽

Imaging Data ◽

Fluid Attenuated Inversion Recovery ◽

Patient Prognosis

Objective: To explore the relation between diffusion-weighted and susceptibility weighted imaging (DWI-SWI) mismatch and collateral circulation or prognosis in patients with occluded M1 segments of middle cerebral artery (MCA).Methods: We enrolled 59 patients with MCA M1-segment occlusion for a retrospective review of baseline clinical and imaging data. As markers of circulatory collaterals, prominent laterality of posterior (PLPCA) and anterior (PLACA) cerebral arteries on magnetic resonance angiography (MRA) studies and a hyperintense vessel sign (HVS) on T2 fluid-attenuated inversion recovery (FLAIR) images were collectively scored. The extent of acute cerebral infarction was then quantified on DWI, using the Alberta Stroke Program Early CT Score (DWI-ASPECTS). Hypointensity vessel sign prominence (PVS) was also evaluated by SWI and similarly scored (SWI-ASPECT) to calculate DWI-SWI mismatch [(DWI-ASPECTS) – (SWI-ASPECTS)], ranging from −10 to 10 points.Results: DWI-SWI mismatch showed significant associations with PLPCA, PLACA, HVS prominence, and collective collateral scores (all, p < 0.05). National Institutes of Health Stroke Scale (NIHSS), DWI-SWI mismatch, and DWI-ASPECTS also differed significantly according to patient prognosis (good vs. poor) after MCA M1-segment occlusion (p < 0.05). In binary logistic regression analyses, NIHSS and DWI-SWI mismatch emerged as independent prognostic factors (p < 0.05).Conclusions: Collateral circulation may be an important aspect of DWI-SWI mismatch, which in this study correlated with prognostic outcomes of MCA M1-segment occlusion.

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Abstract WP430: Endothelial Cell Collection from Ipsilateral Middle Cerebral Artery in Acute Ischemic Stroke

Stroke ◽

10.1161/str.48.suppl_1.wp430 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Sunil A Sheth ◽

Abhishek Verma ◽

David S Liebeskind ◽

Jeffrey L Saver ◽

Gary Duckwiler ◽

...

Keyword(s):

Ischemic Stroke ◽

Endothelial Cell ◽

Middle Cerebral Artery ◽

Acute Ischemic Stroke ◽

Cerebral Artery ◽

Critical Role ◽

Early Time ◽

Stent Retriever ◽

Positive Controls

Introduction: The cerebrovascular endothelium plays a critical role in the pathogenesis of and response to acute ischemic stroke (AIS). To date, techniques to study its function have relied on animal and in vitro models. A robust method of endothelial cell (EC) capture in patients with AIS at early time points, from within the ischemic region, could greatly advance our understanding of cerebrovascular injury. Method: Patients undergoing thrombectomy for middle cerebral artery occlusion (MCA) within 8 hours of onset were offered enrollment if the pass of their stent-retriever device occurred directly into a distal access catheter in the proximal M1 segment, limiting exposure of the device to only the MCA. After retrieval, ECs adherent to the devices were retrieved and stained for EC (CD31) and leukocyte (CD45) markers. EC identity and yield were confirmed by flow cytometry with simultaneous immuno-fluorescence microscopy. Cultured human ECs were used as positive controls. The EC fraction was defined as CD31 + CD45 - with size and morphological features consistent with the positive controls. Results: ECs from stent-retriever devices (n=3) were collected and pooled. Approximately 8% of the collected cells represented ECs. EC collected from the stent-retrievers demonstrated highly similar shape, morphology and antibody staining patterns compared to the positive controls (Figure). Conclusions: Here we provide the first demonstration of a rapid post-thrombectomy method for reliable harvesting of cerebral ECs in humans. The ability to capture these cells in patients with AIS within hours of symptom onset opens many avenues of exploration for determining the role of ECs in AIS.

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Proximal hyper-intense vessel sign on initial FLAIR MRI in hyper-acute middle cerebral artery ischemic stroke: a retrospective observational study

Acta Radiologica ◽

10.1177/0284185120946718 ◽

2020 ◽

pp. 028418512094671 ◽

Cited By ~ 1

Author(s):

Dong Hyuk Shin ◽

Sang Kuk Han ◽

Jang Hee Lee ◽

Pil Cho Choi ◽

Sang O Park ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Cerebral Arteries ◽

Brain Mri ◽

Large Vessel ◽

Resonance Imaging ◽

Vessel Occlusion ◽

Vessel Stenosis

Background A hyper-intense vessel sign on fluid attenuated inversion recovery magnetic resonance imaging (FHV) represents slow blood flow in the cerebral arteries. Purpose To investigate the relationship between the proximal FHV (pFHV) on initial magnetic resonance imaging (MRI) and the status of the culprit vessel (stenosis, obstruction) in hyper-acute strokes affecting the territory of the middle cerebral artery (MCA). Material and Methods The study participants consisted of 105 patients presenting to the emergency department (ED) with acute MCA infarction within 4.5 h of onset of symptoms. Patients underwent brain MRI within 45 min of arrival at the ED and angiography within 2 h of arrival. Culprit vessel status and presence of a pFHV on initial MRI were investigated retrospectively. Results The pFHV was observed in 71/105 (67.6%) patients who presented with a hyper-acute MCA infarction. All patients with hyper-acute MCA infarction caused by internal carotid artery (90.6% caused by M1 occlusion, 92.9% caused by M2 occlusion) showed a pFHV on initial MRI. After logistic regression analysis, the presence of a pFHV showed significant positive correlation with large vessel occlusion (adjusted odds ratio [OR] 34.533, 95% confidence interval [CI] 9.781–121.926; P < 0.001). A pFHV was not associated with severe large vessel stenosis. Conclusion A pFHV is independently representative of the acute occlusion of intervention-eligible proximal arteries within the territory of the MCA. If a patient with a hyper-acute MCA infarction shows a pFHV, aggressive flow augmentation strategies and early activation of intervention team should be warranted for best patient outcome.

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Transcranial Doppler Enhanced Thrombolysis for Embolic Occlusion of Major Cerebral Arteries

Interventional Neuroradiology ◽

10.1177/15910199030090s117 ◽

2003 ◽

Vol 9 (1_suppl) ◽

pp. 129-132

Author(s):

T. Yamanome ◽

M. Sasoh ◽

Y. Kubo ◽

Y. Nishikawa ◽

H. Endoh ◽

...

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Basilar Artery ◽

Transcranial Doppler ◽

Cerebral Arteries ◽

Ultrasound Irradiation ◽

Haemorrhagic Transformation ◽

Good Outcome

For the treatment of 11 patients with hyperacute embolic occlusion of major cerebral arteries (ten with occlusion of middle cerebral artery and one with occlusion of basilar artery), TCD-enhanced thrombolysis (TCDET) was performed in combination with ultrasound irradiation, using diagnostic transcranial Doppler (TCD) (TC2-64B: 2MHz, 100mW/cm2, pulsed wave) (TCDET group), and the effectiveness of this procedure was compared with that of local intra-arterial fibrinolysis (LIF) in 45 patients with embolic occlusion of the middle cerebral artery (LIF group). Regarding dose of TPA, the LIF group used 1046.7 ± 607.8 units and the TCDET group 700.0 ± 431.3 units (p < 0.05). Regarding time technically required to attain recanalization, the LIF group required 68.2 minutes, and the TCDET group 28.6 minutes. A good outcome was noted in 60.8% of the LIF group and 64% of the TCDET group. Haemorrhagic transformation was observed in 7.8% of the LIF group and in 0% of the TCDET group. No complications due to TCD irradiation were observed in the TCDET group. These findings suggest that TCDET can be an effective method of achieving recanalization.

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Experimental and biological variation of three-dimensional transcranial Doppler measurements

Journal of Applied Physiology ◽

10.1152/jappl.1993.75.6.2805 ◽

1993 ◽

Vol 75 (6) ◽

pp. 2805-2810 ◽

Cited By ~ 64

Author(s):

L. L. Thomsen ◽

H. K. Iversen

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Transcranial Doppler ◽

Coefficient Of Variation ◽

Cerebral Arteries ◽

Three Dimensional ◽

Low Frequency ◽

Control Groups ◽

Mean Velocity ◽

Low Frequency Oscillations

A new transcranial Doppler system (3-D Transscan, Eden Medizinische Elektronik) was evaluated in relation to sex, age, intersubject, interobserver, side-to-side, and day-to-day variation. Fifty-eight healthy volunteers participated (aged 18–80 yr). Mean velocity was higher in females than in males and decreased with age. The coefficient of variation in the middle cerebral artery was 26% between subjects, 20% between sides, 16% between days, 13% between observers, and 7% during 5 min. The coefficient of variation was higher in the anterior and posterior cerebral arteries. Bruits were heard in 35 subjects, 24 females and 11 males (P = 0.002). When middle cerebral artery velocity was monitored, high- and low-frequency oscillations were found, with a mean frequency of 5 and 1.6/min, respectively. These variations underline the necessity of standardized conditions and very carefully matched control groups in studies using transcranial Doppler. This is especially important when expected changes are small and easy to overlook, as in studies of normal physiological responses and migraine.

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