Peroxynitrite diminishes myogenic activity and is associated with decreased vascular smooth muscle F-actin in rat posterior cerebral arteries
| Autor: | Nicole DeLance, Matthew J. Maneen, Lisa Vitullo, Marilyn J. Cipolla, Rachael M. Hannah |
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| Rok vydání: | 2006 |
| Předmět: |
Male
Vascular smooth muscle Time Factors Myogenic contraction Cerebral arteries Blood Pressure Filamentous actin Muscle Smooth Vascular chemistry.chemical_compound Ischemia Peroxynitrous Acid Medicine Animals Humans Rats Wistar Advanced and Specialized Nursing Posterior Cerebral Artery Microscopy Confocal business.industry Nitrotyrosine Brain Infarction Middle Cerebral Artery Anatomy Cerebral Arteries medicine.disease Molecular biology Actins Rats Peroxynitrous acid chemistry Reperfusion Injury Tyrosine Neurology (clinical) Cardiology and Cardiovascular Medicine business Reactive Oxygen Species Reperfusion injury Peroxynitrite |
| Zdroj: | Stroke. 37(3) |
| ISSN: | 1524-4628 |
| Popis: | Background and Purpose— This study investigated the effect of peroxynitrite (ONOO − ) on pressure-induced myogenic activity and vascular smooth muscle (VSM) actin of isolated posterior cerebral arteries (PCAs). Methods— Histochemical staining of nitrotyrosine (NT) was used to demonstrate the presence of ONOO − in the cerebrovasculature after 1 hour of middle cerebral artery occlusion with 30 minutes of reperfusion. To determine the effect of ONOO − on pressure-induced myogenic activity, third-order PCAs from nonischemic animals were isolated and mounted in an arteriograph chamber. Diameter in response to changes in pressure was determined in the absence and presence of ONOO − (10 −8 to 10 −4 mol/L). Filamentous actin (F-actin) and globular actin (G-actin) were quantified using confocal microscopy in PCAs with and without exposure to ONOO − . Results— NT staining of vascular cells was greater in ischemic brain versus sham animals (56±3% versus 35±3%; P − (≤10 −6 mol/L) to isolated PCAs caused constriction from 129±16 μm to 115±15 μm ( P 10 −6 mol/L caused dilation of spontaneous tone and loss of myogenic activity in the physiological range of 50 to 125 mm Hg, increasing diameter from 130±6 to 201±5 μm at 75 mm Hg ( P P Conclusions— This study demonstrates that ONOO − affects the myogenic activity of cerebral arteries and causes F-actin depolymerization in VSM, a consequence that could promote vascular damage during reperfusion injury and further brain injury. |
| Databáze: | OpenAIRE |
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