Endothelin-1 Overexpression Leads to Further Water Accumulation and Brain Edema after Middle Cerebral Artery Occlusion via Aquaporin 4 Expression in Astrocytic End-Feet

2005 ◽  
Vol 25 (8) ◽  
pp. 998-1011 ◽  
Author(s):  
Amy CY Lo ◽  
Ann YS Chen ◽  
Victor KL Hung ◽  
Lai Ping Yaw ◽  
Maggie KL Fung ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Cerebral Edema ◽  
Artery Occlusion ◽  
Aquaporin 4 ◽  
Brain Morphology ◽  
Endothelin 1 ◽  
Arterial Blood ◽  
Cerebral Artery Occlusion

Stroke patients have increased levels of endothelin-1 (ET-1), a strong vasoconstrictor, in their plasma or cerebrospinal fluid. Previously, we showed high level of ET-1 mRNA expression in astrocytes after hypoxia/ischemia. It is unclear whether the contribution of ET-1 induction in astrocytes is protective or destructive in cerebral ischemia. Here, we generated a transgenic mouse model that overexpress ET-1 in astrocytes (GET-1) using the glial fibrillary acidic protein promoter to examine the role of astrocytic ET-1 in ischemic stroke by challenging these mice with transient middle cerebral artery occlusion (MCAO). Under normal condition, GET-1 mice showed no abnormality in brain morphology, cerebrovasculature, absolute cerebral blood flow, blood-brain barrier (BBB) integrity, and mean arterial blood pressure. Yet, GET-1 mice subjected to transient MCAO showed more severe neurologic deficits and increased infarct, which were partially normalized by administration of ABT-627 (ETA antagonist) 5 mins after MCAO. In addition, GET-1 brains exhibited more Evans blue extravasation and showed decreased endothelial occludin expression after MCAO, correlating with higher brain water content and increased cerebral edema. Aquaporin 4 expression was also more pronounced in astrocytic end-feet on blood vessels in GET-1 ipsilateral brains. Our current data suggest that astrocytic ET-1 has deleterious effects on water homeostasis, cerebral edema and BBB integrity, which contribute to more severe ischemic brain injury.

scholarly journals Alleviation of Cerebral Infarction of Rats With Middle Cerebral Artery Occlusion by Inhibition of Aquaporin 4 in the Supraoptic Nucleus

ASN NEURO ◽  
2020 ◽  
Vol 12 ◽  
pp. 175909142096055 ◽  
Author(s):  
Dan Cui ◽  
Shuwei Jia ◽  
Jiawei Yu ◽  
Dongyang Li ◽  
Tong Li ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Infarction ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Supraoptic Nucleus ◽  
Artery Occlusion ◽  
Aquaporin 4 ◽  
Vasopressin Neurons ◽  
Cerebral Artery Occlusion

In ischemic stroke, vasopressin hypersecretion is a critical factor of cerebral swelling and brain injury. To clarify neural mechanisms underlying ischemic stroke-evoked vasopressin hypersecretion, we observed the effect of unilateral permanent middle cerebral artery occlusion (MCAO) in rats on astrocytic plasticity and vasopressin neuronal activity in the supraoptic nucleus (SON) as well as their associated cerebral injuries. MCAO for 8 hr caused cerebral infarction in the MCAO side where water contents also increased. Immunohistochemical examination revealed that the percentage of phosphorylated extracellular signal-regulated protein kinase 1/2 (pERK1/2)-positive vasopressin neurons in the SON of MCAO side was significantly higher than that in non-MCAO side and in sham group. In the cortex, pERK1/2 and aquaporin 4 expressions increased significantly in the infarction area, while glial fibrillary acidic protein (GFAP) reduced significantly compared with the noninfarction side in brain cortex. Microinjection of N-(1,3,4-Thiadiazolyl)nicotinamide-020 [TGN-020, a specific blocker of aquaporin 4] into the SON blocked MCAO-evoked increases in pERK1/2 in the SON as well as the reduction of GFAP and the increase in pERK1/2 and aquaporin 4 in the infarction area of the cortex. Finally, oxygen and glucose deprivation reduced GFAP expression and the colocalization and molecular association of GFAP with aquaporin 4 in the SON in brain slices. These effects were blocked by TGN-020 and/or phloretin, a blocker of astrocytic volume-regulated anion channels. These findings indicate that blocking aquaporin 4 in the SON may reduce the activation of vasopressin neurons and brain injuries elicited by vasopressin during ischemic stroke.

Adenosine and cerebral capillary perfusion and blood flow during middle cerebral artery occlusion

1989 ◽  
Vol 257 (5) ◽  
pp. H1656-H1662
Author(s):  
M. Anwar ◽  
H. R. Weiss
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Brain Regions ◽  
Artery Occlusion ◽  
Capillary Perfusion ◽  
Arterial Blood ◽  
Cerebral Artery Occlusion

The effects of adenosine on regional cerebral blood flow and indexes of the total and perfused microvascular bed were studied after 1 h of middle cerebral artery occlusion in the anesthetized rat. Iodo[14C]antipyrine was used to determine cerebral blood flow. Fluorescein isothiocyanate-dextran was used to study the perfused microvasculature, and an alkaline phosphatase stain was used to identify the total bed. Mean arterial blood pressure was significantly reduced by adenosine. Cerebral blood flow increased significantly by 75%, except in the flow-restricted cortex where flow averaged 28 +/- 15 (SD) ml.min-1.100 g-1 in control and 34 +/- 33 ml.min-1.100 g-1 in adenosine-treated animals. No significant regional structural differences were observed within the microvascular beds of the two groups. The percentage of the microvascular volume perfused increased significantly in all brain regions in the adenosine-treated rats, including the flow-restricted cortex. The percent perfused arteriolar volume in the flow-restricted cortex was 30 +/- 12% in control and 95 +/- 3% in adenosine-treated animals. Similar values for the capillary bed were 22 +/- 10% in control and 54 +/- 3% in adenosine-treated rats. These results indicate a maintenance of flow with a reduction in diffusion distances in the flow-restricted cortex after treatment with adenosine.

scholarly journals A New Primate Model of Focal Stroke: Endothelin-1—Induced Middle Cerebral Artery Occlusion and Reperfusion in the Common Marmoset

2004 ◽  
Vol 24 (1) ◽  
pp. 24-41 ◽  
Author(s):  
David Virley ◽  
Sarah J. Hadingham ◽  
Jenny C. Roberts ◽  
Belinda Farnfield ◽  
Heather Elliott ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Common Marmoset ◽  
Artery Occlusion ◽  
Primate Model ◽  
Endothelin 1 ◽  
The Common ◽  
Cerebral Artery Occlusion

The purpose of the present set of studies was to develop a new primate model of focal ischemia with reperfusion for long-term functional assessment in the common marmoset. Initially, the cerebral vascular anatomy of the marmoset was interrogated by Araldite-cast and ink-perfusion methods to determine the feasibility of an intravascular surgical approach. The methods showed that the internal carotid artery was highly tortuous in its passage, precluding the development of an extracranial method of inducing temporary middle cerebral artery occlusion in the marmoset. A pilot dose-response study investigated an intracranial approach of topically applying endothelin-1 (ET-1) to the M2 portion of the middle cerebral artery in a small sample of marmosets for up to 6 hours (n = 2 or 3 per group). Dose-dependent reductions in middle cerebral artery vessel caliber followed by gradual reperfusion were inversely related to increases in corrected lesion volume after ET-1 treatment, relative to vehicle control application. Finally, the functional consequences of ET-1–induced lesions to the M2 vascular territory were assessed up to 24 hours after surgery using the optimal dose established in the pilot study (2.5 nmol/25 μL). ET-1–treated marmosets (n = 4) showed marked contralateral motor deficits in grip strength and retrieval of food rewards and contralateral sensory/motor neglect towards tactile stimulation, relative to their ipsilateral side and vehicle-treated marmosets (n = 4). Strong correlations were shown between contralateral impairments and histopathologic parameters, which revealed unilateral putamen and cortical damage to the middle cerebral artery territory. No deficits were shown on general mobility, and self-care was promptly resumed in ET-1 marmosets after surgery. These results show that this novel model of ischemia with reperfusion in the marmoset has the potential to assess long-term function and to gauge the efficacy of novel therapeutic strategies targeted for clinical stroke.

Behavioural assessment of endothelin-1 induced middle cerebral artery occlusion in the rat

Neuroreport ◽  
1995 ◽  
Vol 6 (7) ◽  
pp. 1067-1071 ◽  
Author(s):  
H. M. Marston ◽  
E. S. L. Faber ◽  
J. H. Crawford ◽  
S. P. Butcher ◽  
J. Sharkey
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Artery Occlusion ◽  
Endothelin 1 ◽  
Behavioural Assessment ◽  
Cerebral Artery Occlusion
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