Facultad de Medicina, Universidad de Morón - Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.
Int J Biochem Cell Biol. 2010 Dec;42(12):1931-5. doi: 10.1016/j.biocel.2010.08.019. Epub 2010 Sep 15.
Nicotine is the main psychoactive substance present in tobacco, targeting neuronal nicotinic acetylcholine receptors. The main effects of nicotine associated with smoking are nicotinic receptor activation, desensitization, and upregulation, with the subsequent modulation of the mesocorticolimbic dopaminergic system. However, there is a lack of a comprehensive explanation of their roles that effectively makes clear how nicotine dependence might be established on those grounds. Receptor upregulation is an unusual effect for a drug of abuse, because theoretically this implies less need for drug consumption. Receptor upregulation and receptor desensitization are commonly viewed as opposite, homeostatic mechanisms. We here review the available information on smoking addiction, especially under a recently presented model of nicotine dependence. In this model both receptor upregulation and receptor desensitization are responsible for establishing a biochemical mechanism of nicotine dependence, which have an important role in starting and maintaining tobacco addiction.
尼古丁是烟草中存在的主要精神活性物质，作用于神经元烟碱型乙酰胆碱受体。与吸烟相关的尼古丁的主要作用是烟碱型受体激活、脱敏和上调，随后调节中脑边缘多巴胺能系统。然而，目前还缺乏对其作用的全面解释，无法有效地阐明尼古丁依赖可能基于哪些机制。受体上调是一种滥用药物的异常效应，因为从理论上讲，这意味着对药物消费的需求减少。受体上调和受体脱敏通常被视为相反的、自身平衡的机制。我们在此综述了有关吸烟成瘾的现有信息，特别是在最近提出的尼古丁依赖模型下。在该模型中，受体上调和受体脱敏都负责建立尼古丁依赖的生化机制，该机制在启动和维持烟草成瘾方面起着重要作用。
