Sobey C G, Faraci F M, Piegors D J, Heistad D D
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242-1081, USA.
Stroke. 1996 May;27(5):927-33. doi: 10.1161/01.str.27.5.927.
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.
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.
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.
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.
本研究检验了以下假设，即颈动脉和眼动脉的功能异常在动脉粥样硬化结构异常消退之前，可能在短期动脉粥样硬化消退后得到改善。
我们研究了动脉粥样硬化的短期饮食治疗对颈动脉和眼血管在体内对血清素以及胶原蛋白诱导的血小板活化的反应的影响。研究了三组猴子：正常食蟹猴、喂食致动脉粥样硬化饮食34个月的猴子以及喂食消退饮食8.6±1.1个月（平均值±标准误）的动脉粥样硬化猴子。我们测量了颈动脉血流变化（使用多普勒探头）、视网膜血流变化（使用微球）以及颈内动脉直径变化（使用定量血管造影）。在体外对颈内动脉环进行了乙酰胆碱介导的内皮依赖性舒张研究。
正常猴子对血清素和胶原蛋白的反应均使颈动脉血流增加，动脉粥样硬化猴子对这两种物质的反应均使血流减少，而在消退后恢复至正常。血清素对正常猴子的视网膜血流几乎没有影响，而在动脉粥样硬化猴子中使视网膜血流显著减少；消退后对血清素的血管收缩反应降低。胶原蛋白激活血小板在正常猴子中增加血流，在动脉粥样硬化猴子中减少血流，消退后影响不大。颈内动脉反应的改变与颈动脉和眼血流的变化一致。体外内皮依赖性舒张功能在动脉粥样硬化时受损，消退后恢复至正常。尽管胆固醇酯显著减少，但消退猴子的颈总动脉和眼动脉粥样硬化病变的内膜面积并未减少。
在动脉粥样硬化消退的几个月内，颈动脉和眼动脉的内皮功能以及对血清素和血小板活化的高反应性恢复正常。功能改善与动脉粥样硬化病变中脂质的吸收有关，但内膜病变大小几乎没有减小。
