Effect of short-term regression of atherosclerosis on reactivity of carotid and retinal arteries
| Autor: | Christopher G. Sobey, Donald J. Piegors, Donald D. Heistad, Frank M. Faraci |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Male
Nitroprusside medicine.medical_specialty Serotonin Arteriosclerosis Retinal Artery Muscle Relaxation In Vitro Techniques Dinoprost Lesion chemistry.chemical_compound Reference Values Internal medicine medicine.artery medicine Animals Platelet activation Advanced and Specialized Nursing business.industry Vascular disease Retinal Blood flow Anatomy medicine.disease Acetylcholine Macaca fascicularis medicine.anatomical_structure Cholesterol chemistry Regional Blood Flow Cardiology Diet Atherogenic Neurology (clinical) medicine.symptom Internal carotid artery Cardiology and Cardiovascular Medicine business Vasoconstriction Carotid Artery Internal Artery Muscle Contraction |
| Zdroj: | Stroke. 27(5) |
| ISSN: | 0039-2499 |
| Popis: | Background and Purpose This study tested the hypothesis that functional abnormalities of carotid and ocular arteries may improve after short-term regression of atherosclerosis, before regression of structural abnormalities. Methods We examined effects of short-term dietary treatment of atherosclerosis on carotid and ocular vascular responses to serotonin and to platelet activation by collagen in vivo. Three groups of monkeys were studied: normal cynomolgus monkeys, monkeys fed an atherogenic diet for 34 months, and atherosclerotic monkeys that were fed a regression diet for 8.6±1.1 months (mean±SE). We measured changes in carotid blood flow (using a Doppler probe), retinal blood flow (using microspheres), and diameter of the internal carotid artery (using quantitative angiography). Endothelium-dependent relaxation to acetylcholine was studied in rings of internal carotid artery in vitro. Results Carotid blood flow increased in response to both serotonin and collagen in normal monkeys, decreased in response to both agents in atherosclerotic monkeys, and was restored toward normal after regression. Serotonin had little effect on retinal blood flow in normal monkeys and produced a marked decrease in retinal blood flow in atherosclerotic monkeys; the vasoconstrictor response to serotonin was reduced after regression. Activation of platelets by collagen increased blood flow in normal monkeys, decreased blood flow in atherosclerotic monkeys, and had little effect after regression. Alterations in responses of the internal carotid artery were consistent with changes in carotid and ocular blood flow. Endothelium-dependent relaxation in vitro was impaired by atherosclerosis and was restored toward normal by regression. There was no reduction in intimal area of the atherosclerotic lesion in common carotid and ophthalmic arteries from regression monkeys, despite a marked reduction in cholesteryl ester. Conclusions Within a few months of regression of atherosclerosis, endothelial function and hyperresponsiveness of carotid and ocular arteries to serotonin and platelet activation return toward normal. Functional improvement is associated with resorption of lipid from atherosclerotic lesions, but with little reduction in size of intimal lesions. |
| Databáze: | OpenAIRE |
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