Effect of Tetrahydrobiopterin on Endothelial Function in Canine Middle Cerebral Arteries

1996 ◽  
Vol 79 (2) ◽  
pp. 336-342 ◽  
Author(s):  
Masato Tsutsui ◽  
Sheldon Milstien ◽  
Zvonimir S. Katusic
Keyword(s):  
Endothelial Function ◽  
Cerebral Arteries ◽  
Middle Cerebral Arteries

scholarly journals Can Myogenic Tone Protect Endothelial Function? Integrating Myogenic Activation and Dilator Reactivity for Cerebral Resistance Arteries in Metabolic Disease

2021 ◽  
pp. 1-15
Author(s):  
Brayden D. Halvorson ◽  
John J. McGuire ◽  
Krishna K. Singh ◽  
Joshua T. Butcher ◽  
Julian H. Lombard ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Group Treatment ◽  
Vascular Function ◽  
Cerebral Arteries ◽  
Resistance Arteries ◽  
Multiple Risk Factors ◽  
Cerebrovascular Function ◽  
Obese Zucker Rat ◽  
Middle Cerebral Arteries ◽  
Slope Treatment

The obese Zucker rat (OZR) manifests multiple risk factors for impaired cerebrovascular function, including hypertension and insulin resistance although how they combine to produce integrated vascular function is unclear. As studies have suggested that myogenic activation (MA) severity for middle cerebral arteries (MCAs) may be proportional to hypertension severity, we hypothesized that MA will negatively correlate with dilator reactivity in OZR. MA of MCA from OZR was divided into low, medium, and high based on the slope of MA, while MCA reactivity and vascular metabolite bioavailability were assessed in all groups. Endothelium-dependent dilation of MCA in OZR was attenuated and correlated with the MA slope. Treatment of OZR MCA with TEMPOL (antioxidant) improved dilation in low or medium MA groups, but had less impact on high MA. Alternatively, treatment with gadolinium to normalize MA in OZR had reduced impact on dilator reactivity in MCA from low and medium MA groups, but improved responses in the high group. Treatment with both agents resulted in dilator responses that were comparable across all groups. These results suggest that, under conditions with stronger MA, endothelial function may receive some protection despite the environment, potentially from the ability of MCA to reduce wall tension despite increased pressure.

scholarly journals Restoration of Endothelial Function inPparα−/−Mice by Tempol

PPAR Research ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Neerupma Silswal ◽  
Nikhil Parelkar ◽  
Jon Andresen ◽  
Michael J. Wacker
Keyword(s):  
Endothelial Function ◽  
Cerebral Arteries ◽  
Lipoprotein Metabolism ◽  
Vascular Wall ◽  
Nuclear Hormone Receptor ◽  
Peroxisome Proliferator ◽  
Resistance Arteries ◽  
Peroxisome Proliferator Activated Receptor ◽  
Middle Cerebral Arteries ◽  
Ros Scavenger

Peroxisome proliferator activated receptor alpha (PPARα) is one of the PPAR isoforms belonging to the nuclear hormone receptor superfamily that regulates genes involved in lipid and lipoprotein metabolism. PPARαis present in the vascular wall and is thought to be involved in protection against vascular disease. To determine if PPARαcontributes to endothelial function, conduit and cerebral resistance arteries were studied inPparα−/−mice using isometric and isobaric tension myography, respectively. Aortic contractions to PGF2αand constriction of middle cerebral arteries to phenylephrine were not different between wild type (WT) andPparα−/−; however, relaxation/dilation to acetylcholine (ACh) was impaired. There was no difference in relaxation between WT andPparα−/−aorta to treatment with a nitric oxide (NO) surrogate indicating impairment in endothelial function. Endothelial NO levels as well as NO synthase expression were reduced inPparα−/−aortas, while superoxide levels were elevated. Two-week feeding with the reactive oxygen species (ROS) scavenger, tempol, normalized ROS levels and rescued the impaired endothelium-mediated relaxation inPparα−/−mice. These results suggest thatPparα−/−mice have impaired endothelial function caused by decreased NO bioavailability. Therefore, activation of PPARαreceptors may be a therapeutic target for maintaining endothelial function and protection against cardiovascular disease.

DIFFICULTIES IN DIAGNOSING MOYA-MOYA DISEASE (CLINICAL CASE)

2020 ◽  
pp. 48-53
Author(s):  
Novikova I.N. ◽  
Popova T.F. ◽  
Gribacheva I.A. ◽  
Petrova E.V. ◽  
Marushchak A.A. ◽  
...  
Keyword(s):  
Cerebral Angiography ◽  
Neurological Disorders ◽  
Clinical Case ◽  
Carotid Arteries ◽  
Internal Carotid ◽  
Cerebral Arteries ◽  
Moya Moya Disease ◽  
Middle Cerebral Arteries ◽  
Internal Carotid Arteries ◽  
Made In

Moya-Moya disease is a rare progressive chronic cer-ebrovascular disease characterized by a narrowing of the lumen of the intracranial segments of the internal carotid arteries, as well as the initial segments of the anterior and middle cerebral arteries with the devel-opment of a network of small vascular anastomoses. Violations of blood supply due to occlusion lead to the development of ischemic strokes in the correspond-ing pools, and ruptures of vascular anastomoses - to the development of hemorrhagic strokes, causing a variety of neurological disorders. The article presents a clinical case of Moya-Moya disease in a 31-year-old patient. The disease was manifested by acute disorders of cerebral circulation in ischemic and hemorrhagic types. The diagnosis was made in accordance with the diagnostic criteria of the disease based on the data of endovascular cerebral angiography.

Modulation of cerebral arterial tone by endothelium-derived relaxing factor

1993 ◽  
Vol 264 (4) ◽  
pp. H1245-H1250 ◽  
Author(s):  
J. E. Brian ◽  
R. H. Kennedy
Keyword(s):  
Nitric Oxide ◽  
Muscle Tone ◽  
Cerebral Arteries ◽  
Maximum Tension ◽  
Relaxing Factor ◽  
Middle Cerebral Arteries ◽  
Endothelium Derived Relaxing Factor ◽  
Vascular Smooth Muscle Tone ◽  
Dose Dependent ◽  
Arterial Tone

This study was designed to further elucidate the role of the endothelium in regulation of cerebral vascular smooth muscle tone. Dose-dependent vasoconstrictive effects of serotonin (5-HT) were examined in endothelium-intact and endothelium-denuded ring segments prepared from canine basilar and middle cerebral arteries. Some preparations were pretreated with 10(-5) M N omega-nitro-L-arginine (L-NNA), an agent that inhibits the production of L-arginine-derived nitric oxide, one of the compounds proposed to be endothelium-derived relaxing factor. L-NNA alone elicited marked dose-dependent increases in tension in endothelium-intact preparations; a significantly smaller response was seen in endothelium-denuded preparations. The effects of L-NNA on endothelium-intact preparations were partially reversed by washing and treatment with L-arginine. The maximum tension induced by 5-HT was approximately doubled by removal of the endothelium as well as by L-NNA treatment of endothelium-intact preparations; a slight increase in maximum tension occurred in endothelium-denuded preparations treated with L-NNA. The concentration of 5-HT producing half-maximal contraction (ED50) was not affected by L-NNA. These data suggest that L-arginine-derived nitric oxide modulates canine cerebral arterial tone in both the resting state and during contraction with 5-HT.

scholarly journals Cerebral Hemodynamics and Intracranial Compliance Impairment in Critically Ill COVID-19 Patients: A Pilot Study

2021 ◽  
Vol 11 (7) ◽  
pp. 874
Author(s):  
Sérgio Brasil ◽  
Fabio Silvio Taccone ◽  
Sâmia Yasin Wahys ◽  
Bruno Martins Tomazini ◽  
Filippo Annoni ◽  
...  
Keyword(s):  
Critically Ill ◽  
Cerebral Arteries ◽  
Receiver Operating Curve ◽  
Severe Illness ◽  
Mean Flow ◽  
Non Invasive ◽  
Intracranial Compliance ◽  
Middle Cerebral Arteries ◽  
Primary Composite Outcome ◽  
Cerebrovascular Hemodynamics

Introduction: One of the possible mechanisms by which the new coronavirus (SARS-Cov2) could induce brain damage is the impairment of cerebrovascular hemodynamics (CVH) and intracranial compliance (ICC) due to the elevation of intracranial pressure (ICP). The main objective of this study was to assess the presence of CVH and ICC alterations in patients with COVID-19 and evaluate their association with short-term clinical outcomes. Methods: Fifty consecutive critically ill COVID-19 patients were studied with transcranial Doppler (TCD) and non-invasive monitoring of ICC. Subjects were included upon ICU admission; CVH was evaluated using mean flow velocities in the middle cerebral arteries (mCBFV), pulsatility index (PI), and estimated cerebral perfusion pressure (eCPP), while ICC was assessed by using the P2/P1 ratio of the non-invasive ICP curve. A CVH/ICC score was computed using all these variables. The primary composite outcome was unsuccessful in weaning from respiratory support or death on day 7 (defined as UO). Results: At the first assessment (n = 50), only the P2/P1 ratio (median 1.20 [IQRs 1.00–1.28] vs. 1.00 [0.88–1.16]; p = 0.03) and eICP (14 [11–25] vs. 11 [7–15] mmHg; p = 0.01) were significantly higher among patients with an unfavorable outcome (UO) than others. Patients with UO had a significantly higher CVH/ICC score (9 [8–12] vs. 6 [5–7]; p < 0.001) than those with a favorable outcome; the area under the receiver operating curve (AUROC) for CVH/ICC score to predict UO was 0.86 (95% CIs 0.75–0.97); a score > 8.5 had 63 (46–77)% sensitivity and 87 (62–97)% specificity to predict UO. For those patients undergoing a second assessment (n = 29), after a median of 11 (5–31) days, all measured variables were similar between the two time-points. No differences in the measured variables between ICU non-survivors (n = 30) and survivors were observed. Conclusions: ICC impairment and CVH disturbances are often present in COVID-19 severe illness and could accurately predict an early poor outcome.

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.

Carotid-Cavernous Fistula Treated with Detachable Balloon during Bilateral Transcranial Doppler Monitoring of Middle Cerebral Arteries

1992 ◽  
Vol 33 (2) ◽  
pp. 145-148 ◽  
Author(s):  
P. H. Nakstad ◽  
J. K. Hald ◽  
W. Sorteberg
Keyword(s):  
Carotid Artery ◽  
Transcranial Doppler ◽  
Cerebral Arteries ◽  
Carotid Cavernous Fistula ◽  
Detachable Balloon ◽  
Cavernous Fistula ◽  
Doppler Technique ◽  
Middle Cerebral Arteries

A traumatic carotid-cavernous fistula was closed with a silicone detachable balloon. Prior to the closure of the fistula, clinical and transcranial Doppler testing was performed in order to evaluate the consequences of a possible occlusion of the carotid artery. A newly developed Doppler technique with bilateral simultaneous velocity recordings of the middle cerebral arteries was useful during the procedure. The detachable balloon was effective in closing the fistula, but collapse of the balloon and the development of an extradural aneurysm was found at control examinations.

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