Hanna Salma Toma
Department of Physiology, University of Saskatchewan, Saskatoon, Canada.
J Cardiovasc Pharmacol. 2006 Mar;47(3):348-58. doi: 10.1097/01.fjc.0000205984.13395.9e.
Smoking is a leading cause of cardiovascular disease, hypertension, myocardial infarction, and stroke. Nicotine is one of the components of cigarette smoke. Nicotine effects on the cardiovascular system reflect the activity of the nicotine receptors centrally and on peripheral autonomic ganglia. It has been found that cigarette smoke extract-induced contraction of porcine coronary arteries is related to superoxide anion-mediated degradation of nitric oxide. Treatment of rabbit aortas with an oxygen free radicals scavenger attenuated cigarette smoke impairment of arterial relaxation. Treatment of smokers with vitamin C, an antioxidant, improved impaired endothelium-dependent reactivity of large peripheral arteries. Thus it appears that chronic smoking and acute exposure to cigarette smoke extract may alter endothelium-dependent reactivity via the production of oxygen derived free radicals. This review discusses the effects of nicotine on resistance arterioles, compliance arteries, smooth muscle cells, and ion channels in the cardiovascular system. We discuss studies performed on humans, nicotine-exposed animals, and cell cultures yielding varying and inconsistent results that may be due to differences in experimental design, species, and the dose of exposure. Nicotine exposure appears to induce a combination of free radical production, vascular wall adhesion, and a reduction of fibrinolytic activity in the plasma.
吸烟是心血管疾病、高血压、心肌梗死和中风的主要病因之一。尼古丁是香烟烟雾的成分之一。尼古丁对心血管系统的影响反映了其在中枢以及外周自主神经节上尼古丁受体的活性。研究发现，香烟烟雾提取物诱导的猪冠状动脉收缩与超氧阴离子介导的一氧化氮降解有关。用氧自由基清除剂处理兔主动脉可减轻香烟烟雾对动脉舒张功能的损害。用抗氧化剂维生素C治疗吸烟者可改善外周大动脉内皮依赖性反应性受损的情况。因此，似乎长期吸烟和急性接触香烟烟雾提取物可能通过产生氧衍生自由基来改变内皮依赖性反应性。这篇综述讨论了尼古丁对心血管系统中阻力小动脉、顺应性动脉、平滑肌细胞和离子通道的影响。我们讨论了对人类、暴露于尼古丁的动物以及细胞培养所进行的研究，这些研究得出了不同且不一致的结果，这可能是由于实验设计、物种和暴露剂量的差异所致。尼古丁暴露似乎会导致自由基产生、血管壁黏附以及血浆中纤维蛋白溶解活性降低等多种情况。
