Landmark K, Reikvam A
Institutt for farmakoterapi, Oslo.
Tidsskr Nor Laegeforen. 1998 Oct 10;118(24):3805-9.
High levels of cholesterol increase the influx of calcium ions into vascular smooth muscle cells, thereby increasing vascular tone and resistance. Simultaneously, endothelium-dependent (NO-mediated) vasodilatation is inhibited in the arteries. Brief reductions in cholesterol induced by dietary intervention or with lipid lowering therapy normalize endothelial dysfunction, and myocardial perfusion will increase well before any beneficial effects on atherosclerosis are detected. These phenomena may explain, at least in part, that in spite of even small differences in angiographic findings between patients who have undergone treatment and those who have not, lowering lipids will cause major reductions in cardiovascular events. Lowering the levels of cholesterol will alter the content and composition of atherosclerotic plaques, thereby making them more stable. The result is probably a substantial reduction in the frequency of plaque rupture, and if rupture should occur, the thrombotic mechanisms will probably be weaker. Consequently, the risk of a thrombotic occlusion of a coronary vessel will be reduced.
高水平的胆固醇会增加钙离子流入血管平滑肌细胞，从而增加血管张力和阻力。同时，动脉中内皮依赖性（一氧化氮介导）的血管舒张受到抑制。饮食干预或降脂治疗引起的胆固醇短暂降低可使内皮功能障碍恢复正常，并且在检测到对动脉粥样硬化有任何有益作用之前，心肌灌注就会增加。这些现象至少可以部分解释，尽管接受治疗的患者与未接受治疗的患者在血管造影结果上存在微小差异，但降低血脂仍会导致心血管事件大幅减少。降低胆固醇水平会改变动脉粥样硬化斑块的含量和组成，从而使其更稳定。结果可能是斑块破裂的频率大幅降低，如果发生破裂，血栓形成机制可能会更弱。因此，冠状动脉血栓闭塞的风险将降低。
