Biaxial and Failure Mechanical Properties of Passive Rat Middle Cerebral Arteries

2011 ◽  
Author(s):  
E. David Bell ◽  
Rahul S. Kunjir ◽  
Kenneth L. Monson
Keyword(s):  
Mechanical Properties ◽  
Traumatic Brain Injury ◽  
Cerebral Autoregulation ◽  
Cerebral Arteries ◽  
Mechanical Damage ◽  
Cerebral Vasculature ◽  
Cerebral Blood Vessels ◽  
Middle Cerebral Arteries ◽  
And Function ◽  
The Brain

Cerebral blood vessels are critical in maintaining the health and function of the brain, but their function can be disrupted by traumatic brain injury (TBI), which commonly includes damage to these vessels [1]. However, even in cases where there is not apparent mechanical damage to the cerebral vasculature, TBI can induce physiological disruptions that can lead to breakdown of the blood brain barrier or loss of cerebral autoregulation.

Cerebrovascular Dysfunction Following Sub-Failure Axial Stretch

2013 ◽  
Author(s):  
E. David Bell ◽  
Kenneth L. Monson
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cerebral Autoregulation ◽  
Mechanical Damage ◽  
Cerebral Vasculature ◽  
Cerebral Blood Vessels ◽  
Axial Stretch ◽  
Cerebrovascular Dysfunction ◽  
And Function ◽  
The Brain

Cerebral blood vessels are critical in maintaining the health and function of the brain, but their function can be disrupted by traumatic brain injury (TBI), which commonly includes damage to these vessels [1]. However, even in cases where there is not apparent mechanical damage to the cerebral vasculature, TBI can induce physiological disruptions that can lead to breakdown of the blood brain barrier or loss of cerebral autoregulation.

scholarly journals Impaired myogenic response and autoregulation of cerebral blood flow is rescued in CYP4A1 transgenic Dahl salt-sensitive rat

2015 ◽  
Vol 308 (5) ◽  
pp. R379-R390 ◽  
Author(s):  
Fan Fan ◽  
Aron M. Geurts ◽  
Sydney R. Murphy ◽  
Mallikarjuna R. Pabbidi ◽  
Howard J. Jacob ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Arteries ◽  
Cerebral Injury ◽  
Transgenic Rat ◽  
Myogenic Response ◽  
Cerebral Vasculature ◽  
Synthesis Inhibitor ◽  
Middle Cerebral Arteries ◽  
The Brain

We have reported that a reduction in renal production of 20-HETE contributes to development of hypertension in Dahl salt-sensitive (SS) rats. The present study examined whether 20-HETE production is also reduced in the cerebral vasculature of SS rats and whether this impairs the myogenic response and autoregulation of cerebral blood flow (CBF). The production of 20-HETE, the myogenic response of middle cerebral arteries (MCA), and autoregulation of CBF were compared in SS, SS-5BN rats and a newly generated CYP4A1 transgenic rat. 20-HETE production was 6-fold higher in cerebral arteries of CYP4A1 and SS-5BN than in SS rats. The diameter of the MCA decreased to 70 ± 3% to 65 ± 6% in CYP4A1 and SS-5BN rats when pressure was increased from 40 to 140 mmHg. In contrast, the myogenic response of MCA isolated from SS rats did not constrict. Administration of a 20-HETE synthesis inhibitor, HET0016, abolished the myogenic response of MCA in CYP4A1 and SS-5BN rats but had no effect in SS rats. Autoregulation of CBF was impaired in SS rats compared with CYP4A1 and SS-5BN rats. Blood-brain barrier leakage was 5-fold higher in the brain of SS rats than in SS-5BN and SS.CYP4A1 rats. These findings indicate that a genetic deficiency in the formation of 20-HETE contributes to an impaired myogenic response in MCA and autoregulation of CBF in SS rats and this may contribute to vascular remodeling and cerebral injury following the onset of hypertension.

scholarly journals The arteries of the brain base in the degu (Octodon degus Molina 1782)

2014 ◽  
Vol 59 (No. 7) ◽  
pp. 343-348 ◽  
Author(s):  
W. Brudnicki ◽  
B. Skoczylas ◽  
R. Jablonski ◽  
W. Nowicki ◽  
A. Brudnicki ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Basilar Artery ◽  
Internal Carotid ◽  
Cerebral Arteries ◽  
Left Vertebral Artery ◽  
Brain Arteries ◽  
Middle Cerebral Arteries ◽  
The Brain ◽  
Synthetic Latex

The brain arteries derived from 50 adult degu individuals of both sexes were injected with synthetic latex introduced with a syringe into the left ventricle of the heart under constant pressure. After fixation in 5% formalin and brain preparation, it was found that the sources of the brain’s supply of blood are vertebral arteries and the basilar artery formed as a result of their anastomosis. The basilar artery gave rise to caudal cerebellar arteries and then divided into two branches which formed the arterial circle of the brain. The internal carotid arteries in degus, except for one case, were heavily reduced and did not play an important role in the blood supply to the brain. The arterial circle of the brain in 48% of the cases was open from the rostral side. Variation was identified in the anatomy and the pattern of the arteries of the base of the brain in the degu which involved an asymmetry of the descent of caudal cerebellar arteries (6.0%), rostral cerebellar arteries (8%) as well as middle cerebral arteries (12%). In 6% of the individuals double middle cerebral arteries were found. In one out of 50 cases there was observed a reduction in the left vertebral artery and the appearance of the internal carotid artery on the same side. In that case the left part of the arterial circle of the brain was supplied with blood by an internal carotid artery, which was present only in that animal.

Adrenergic innervation of the cerebral blood vessels in the rabbit

1971 ◽  
Vol 35 (2) ◽  
pp. 148-154 ◽  
Author(s):  
S. John Peerless ◽  
M. Gazi Yasargil
Keyword(s):  
Basilar Artery ◽  
Cerebral Arteries ◽  
Adrenergic Innervation ◽  
Cerebral Blood Vessels ◽  
Content Type ◽  
Middle Cerebral Arteries ◽  
Transmitter Substance ◽  
Subarachnoid Blood ◽  
Adrenergic Fibers ◽  
Adrenergic Terminals

✓ The Hillarp technique of fluorescent staining of monoamines was used to examine the adrenergic fibers in the cerebral vessels of rabbit brains. These fibers were found to lie wholly within the deeper layers of the adventitia and not within muscle layers. Varicosities were interpreted as representing neural transmitter substance. The basilar artery had a sparse innervation; the anterior cerebral, carotid, and middle cerebral arteries were more richly supplied by adrenergic terminals, with the most dense innervation in the superficial vessels between 100 and 300 µ in diameter. Mild trauma to the basilar artery, as well as subarachnoid blood without trauma, caused the catecholamine reaction to disappear. A marked depletion of adrenergic fibers was also noted after administration of alpha methyl tyrosine and subjection of the animals to extremes of blood pressure.

scholarly journals Differential effects of diet-induced obesity on BKCa β1-subunit expression and function in rat skeletal muscle arterioles and small cerebral arteries

2011 ◽  
Vol 301 (1) ◽  
pp. H29-H40 ◽  
Author(s):  
Lauren Howitt ◽  
Shaun L. Sandow ◽  
T. Hilton Grayson ◽  
Zoe E. Ellis ◽  
Margaret J. Morris ◽  
...  
Keyword(s):  
Cerebral Arteries ◽  
Myogenic Tone ◽  
Cremaster Muscle ◽  
Α Subunit ◽  
Differential Effects ◽  
Subunit Protein ◽  
Diet Induced Obesity ◽  
Middle Cerebral Arteries ◽  
Subunit Expression ◽  
And Function

Mechanisms underlying obesity-related vascular dysfunction are unclear. This study examined the effect of diet-induced obesity on expression and function of large conductance Ca2+-activated potassium channel (BKCa) in rat pressurized small resistance vessels with myogenic tone. Male Sprague-Dawley rats fed a cafeteria-style high fat diet (HFD; ∼30% energy from fat) for 16–20 wk were ∼30% heavier than controls fed standard chow (∼13% fat). Obesity did not alter BKCa α-subunit function or α-subunit protein or mRNA expression in vessels isolated from the cremaster muscle or middle-cerebral circulations. In contrast, BKCa β1-subunit protein expression and function were significantly reduced in cremaster muscle arterioles but increased in middle-cerebral arteries from obese animals. Immunohistochemistry showed α- and β1-subunits were present exclusively in the smooth muscle of both vessels. Cremaster muscle arterioles from obese animals showed significantly increased medial thickness, and media-to-lumen ratio and pressurized arterioles showed increased myogenic tone at 30 mmHg, but not at 50–120 mmHg. Myogenic tone was not affected by obesity in middle-cerebral arteries. The BKCa antagonist iberiotoxin constricted both cremaster muscle and middle-cerebral arterioles from control rats; this effect of iberiotoxin was abolished in cremaster muscle arteries only from obese rats. Diet-induced obesity has contrasting effects on BKCa function in different vascular beds, through differential effects on β1-subunit expression. However, these alterations in BKCa function had little effect on overall myogenic tone, suggesting that the mechanisms controlling myogenic tone can be altered and compensate for altered BKCa expression and function.

scholarly journals Ischemic stroke following abuse of Marijuana in a Nigerian adult male

2014 ◽  
Vol 05 (04) ◽  
pp. 417-419 ◽  
Author(s):  
Olalekan Oyinloye ◽  
Donald Nzeh ◽  
Ayodeji Yusuf ◽  
Emmanuel Sanya
Keyword(s):  
Young Adults ◽  
Ischemic Stroke ◽  
Basal Ganglia ◽  
Illicit Drugs ◽  
Cerebral Arteries ◽  
Cannabis Abuse ◽  
The Past ◽  
Middle Cerebral Arteries ◽  
Stroke In The Young ◽  
The Brain

ABSTRACTCannabis is the most widely used illicit drug among adolescents and young adults. Despite its widespread use, only a few reports exist on the association of cannabis use and stroke. A 26-year-old Nigerian male, developed right-sided ischemic stroke few hours after smoking three wraps of cannabis. He had smoked cannabis consistently for the past 4 years prior to the development of the stroke. Known stroke etiology and abuse of other illicit drugs were ruled out from history and investigations. Neuroimaging studies of the brain revealed infarcts in basal ganglia secondary to occlusion of blood flow in the left anterior and middle cerebral arteries. The mechanism of stroke in this patient was thought to be a cannabis-induced vasculopathy. Many cases of stroke in the young are increasingly being seen in hospitals in resource scarce countries. There seems to be a predilection for the basal ganglia in ischemic stroke following cannabis abuse. Therefore, cannabis abuse should be considered in young adults with basal ganglia infarcts, after excluding other known etiologies.

Mechanical Properties of Active and Passive Rat Middle Cerebral Arteries

2002 ◽  
Author(s):  
Rebecca J. Coulson ◽  
Marilyn J. Cipolla ◽  
Lisa Vitullo ◽  
Naomi C. Chesler
Keyword(s):  
Mechanical Properties ◽  
Blood Flow ◽  
Smooth Muscle ◽  
Cell Activation ◽  
Cerebral Arteries ◽  
Disease States ◽  
Middle Cerebral Arteries ◽  
Extracellular Matrix Components ◽  
Brain Tissue Damage

Cerebral arteries play an important role in the regulation of cerebral blood flow through autoregulation, a well established phenomenon which is caused by a combination of myogenic, neuronal and metabolic mechanisms [1]. Myogenic reactivity is the ability of the vascular smooth muscle cells (SMC) to contract in response to stretch or to an increase in transmural pressure (TMP), and to dilate in response to a decrease in TMP [2]. It is this active constriction of arteries within the autoregulatory range that prompts studies of not just passive mechanical properties, but also active mechanical properties. Passive properties provide an understanding of the behavior of the extracellular matrix components of arteries (i.e. collagen and elastin); but, in order to understand how the artery behaves in vivo, it is necessary to understand the mechanical properties with smooth muscle cell activation. Mechanical properties might also be altered if the vessel is diseased or damaged. Ischemia has been shown to reduce vascular tone, which might lead to brain tissue damage during stroke [3]. Therefore studying the mechanical properties of vessels in disease states to determine if they are able to adequately take part in controlling local blood flow is also important.

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