Protection against ischemia and improvement of cerebral blood flow in genetically hypertensive rats by chronic pretreatment with an angiotensin II AT1 antagonist
| Autor: | José A. Terrón, Claudia Bregonzio, Alicia Falcón-Neri, Takeshi Ito, Juan M. Saavedra, Haruki Yamakawa |
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| Rok vydání: | 2002 |
| Předmět: |
Male
medicine.medical_specialty Captopril Nicardipine Ischemia Tetrazoles Angiotensin-Converting Enzyme Inhibitors Blood Pressure Drug Administration Schedule Receptor Angiotensin Type 1 Brain Ischemia Angiotensin Receptor Antagonists Internal medicine Rats Inbred SHR medicine Animals Stroke Antihypertensive Agents Advanced and Specialized Nursing Angiotensin II receptor type 1 business.industry Biphenyl Compounds Brain Infarction Middle Cerebral Artery medicine.disease Calcium Channel Blockers Angiotensin II Rats Candesartan Disease Models Animal Endocrinology Cerebral blood flow Cerebrovascular Circulation Hypertension Benzimidazoles Neurology (clinical) Cardiology and Cardiovascular Medicine business Blood Flow Velocity medicine.drug |
| Zdroj: | Stroke. 33(9) |
| ISSN: | 1524-4628 |
| Popis: | Background and Purpose— Pretreatment with angiotensin II AT 1 receptor antagonists protects against cerebral ischemia. We studied whether modulation of cerebral blood flow (CBF) and morphometric changes in brain arteries participated in this protective mechanism. Methods— We pretreated adult spontaneously hypertensive rats with equally antihypertensive doses of candesartan (0.1 or 0.3 mg/kg per day), nicardipine (0.1 mg/kg per day), or captopril (3.0 mg/kg per day) for 3 or 28 days via subcutaneous osmotic minipumps followed by permanent left middle cerebral artery (MCA) occlusion distal to the origin of the lenticulostriate arteries. We measured CBF by autoradiography with 4-iodo-[ N -methyl- 14 C]antipyrine 3 hours after operation and the areas of infarct and tissue swelling 24 hours after operation. Morphometric changes in the MCA were studied after antihypertensive treatment. Results— Twenty-eight days of candesartan pretreatment decreased the infarct area by 31%; reduced the CBF decrease at the peripheral area of ischemia and the cortical volume of severe ischemic lesion, where CBF was Conclusions— Angiotensin II system inhibition protects against neuronal injury more effectively than calcium channel blockade. Protection after AT 1 receptor blockade is not directly correlated with blood pressure reduction but with normalization of MCA media thickness, leading to increased arterial compliance and reduced CBF decrease during ischemia at the periphery of the lesion. |
| Databáze: | OpenAIRE |
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