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Endothelin-mediated vascular tone following focal cerebral ischaemia in the cat
- Source :
- Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. 16(4)
- Publication Year :
- 1996
-
Abstract
- The actions of Bosentan and PD155080, nonpeptide endothelin receptor antagonists, were examined in feline pial arterioles in situ following middle cerebral artery (MCA) occlusion to gain insight into the cerebrovascular influence of endogenous endothelins in focal cerebral ischaemia. Immediately following permanent MCA occlusion, all pial arterioles overlying the suprsylvian and ectosylvian gyri displayed marked dilatations, which were maintained in a population of vessel but differentiated into sustained constrictions in others. Perivascular subarachnoid microinjections of Bosentan (30 microM), PD155080 (30 microM), and artificial CSF (pH 7.2) were performed between 30 and 210 min following MCA occlusion. The perivascular microapplication of Bosentan (30 microM) and PD155080 (30 microM) around pial vessels overlying the suprasylvian and ectosylvian gyri, which are within the territory of the occluded MCA, elicited in increase in the calibre of postocclusion dilated and constricted pial arterioles. The perivascular microapplication of PD155080 (30 microM) around postocclusion constricted arterioles overlying the ectosylvian and suprasylvian gyri elicited an increase in the calibre of arterioles (69 +/- 49% from preinjection baseline; n = 8). The perivascular microapplication of Bosentan (30 microM) around postocclusion constricted arterioles overlying the ectosylvian and suprasylvian gyri also elicited an increase in the calibre of arterioles (68 +/- 60% from preinjection baseline; n = 13). In contrast, the microapplication of CSF (pH 7.2) elicited small reductions in pial arteriolar calibre of postocclusion constricted arterioles (-8 +/- 13% from preinjection baseline; n = 8). The perivascular microapplication of PD155080 (30 microM) around postocclusion dilated pial arterioles overlying the ectosylvian and suprasylvian gyri elicited an increase in the calibre of arterioles (11 +/- 10% from preinjection baseline; n = 38). The perivascular microapplication of Bosentan (30 microM) around postocclusion dilated arterioles elicited an increase in the calibre of arterioles (16 +/- 15% from preinjection baseline; n = 36). In contrast, the microapplication of CSF (pH 7.2) elicited small reductions in pial arteriolar calibre of postocclusion dilated arterioles (-9 +/- 6% from preinjection baseline; n = 44). Perivascular microapplication of Bosentan or PD155080 had minimal effect on the calibre of pial arterioles on the parasagittal gyrus (anterior cerebral artery territory), although these arterioles had also displayed sustained dilatation following MCA occlusion. These results indicate that contractile factors (whose effects can be reversed with endothelin receptor antagonists) constrict or impair dilatation of cortical resistance arterioles in an acute cerebral ischaemic episode.
- Subjects :
- medicine.hormone
medicine.medical_specialty
Population
Dioxoles
030218 nuclear medicine & medical imaging
Brain Ischemia
Endothelins
03 medical and health sciences
0302 clinical medicine
Reference Values
medicine.artery
Internal medicine
medicine
Carnivora
Animals
education
Cerebrospinal Fluid
education.field_of_study
Sulfonamides
biology
business.industry
Fissipedia
Bosentan
Anatomy
biology.organism_classification
Vasomotor System
Arterioles
medicine.anatomical_structure
Neurology
Vasoconstriction
Cerebrovascular Circulation
Middle cerebral artery
cardiovascular system
Cardiology
Cats
Pia Mater
Female
Neurology (clinical)
Cardiology and Cardiovascular Medicine
Endothelin receptor
business
030217 neurology & neurosurgery
circulatory and respiratory physiology
medicine.drug
Blood vessel
Subjects
Details
- ISSN :
- 0271678X
- Volume :
- 16
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
- Accession number :
- edsair.doi.dedup.....9aa3ce47be4fc124f41d91c4761e0249