Abstract

Nicotine is one of the main chemicals in the cigarettes responsible for addiction formation. Many researches investigating the effects of nicotine on coronary heart disease and atherosclerosis have been published. The robustness of endothelial cells is very important in the development of atherosclerosis. The aim of this study is to evaluate the effect of nicotine exposure on the indicators of endothelial function either by examining the vascular reactivity of aorta taken from rats exposed to nicotine during prenatal (starting by the mating period) and postnatal periods (6 weeks after delivery), or by determining the protein expression of nitric oxide synthase (NOS) enzymes, NADPH oxidase (Nox) and nitrotyrosine. Chronic nicotine exposure at 6 mg/L in drinking water produced a significant decrease in phenylephrine contractility of thoracic aortic rings compared to control and low dose exposure group (0.4 mg/L, p < 0.001). Endothelium-dependent relaxations to acetylcholine increased dose-dependently while no changes were observed in endothelium-independent relaxations to sodium nitroprusside and protein expressions in rat thoracic aorta. It has been concluded that long term nicotine exposure does not have serious effects on endothelial vasodilator response directly and does not change protein expression of NOS or Nox enzymes. However, more studies should be done for the exact mechanisms responsible for the effect of nicotine on endothelial function.

摘要

尼古丁是香烟中导致成瘾的主要化学物质之一。许多调查尼古丁对冠心病和动脉粥样硬化影响的研究已经发表。内皮细胞的健壮性在动脉粥样硬化的发展中非常重要。本研究的目的是通过检查产前（从交配期开始）和产后（分娩后 6 周）暴露于尼古丁的大鼠的主动脉血管反应性来评估尼古丁暴露对内皮功能指标的影响)，或通过测定一氧化氮合酶 (NOS) 酶、NADPH 氧化酶 (Nox) 和硝基酪氨酸的蛋白质表达。p  < 0.001)。内皮依赖性对乙酰胆碱的舒张呈剂量依赖性增加，而在大鼠胸主动脉中对硝普钠的内皮依赖性舒张和蛋白质表达没有观察到变化。已经得出结论，长期尼古丁暴露不会直接对内皮血管扩张剂反应产生严重影响，也不会改变 NOS 或 Nox 酶的蛋白质表达。然而，对于尼古丁对内皮功能影响的确切机制，应该进行更多的研究。