Shiffman S, Zettler-Segal M, Kassel J, Paty J, Benowitz N L, O'Brien G
Department of Psychology, University of Pittsburgh, PA 15260.
Psychopharmacology (Berl). 1992;109(4):449-56. doi: 10.1007/BF02247722.
Although most smokers are nicotine-dependent, recent studies suggest that some very light smokers ("chippers", who smoke fewer than five cigarettes per day) may smoke for decades without developing dependence. It was considered that slowed nicotine elimination and/or reduced nicotine tolerance might underlie chippers' ability to maintain smoking at such low levels. To evaluate this hypothesis, we studied the elimination kinetics and pharmacodynamics of nicotine in chippers and matched regular smokers. Plasma nicotine levels and cardiovascular responses were observed for several hours after subjects were administered uniform doses of tobacco smoke. Chippers did show less chronic nicotine tolerance, but only on some response measures. Their rates of nicotine elimination equaled those of regular smokers. This finding, when coupled with other data about chippers' smoking patterns and nicotine absorption, establish that chippers cannot maintain substantial plasma nicotine levels between cigarettes, and thus suggest that attempts to maintain minimal trough levels of nicotine do not underlie chippers' smoking.
尽管大多数吸烟者对尼古丁有依赖，但最近的研究表明，一些轻度吸烟者（“偶尔吸烟者”，即每天吸烟少于五支）可能吸烟数十年却不会产生依赖。人们认为，尼古丁消除速度减慢和/或尼古丁耐受性降低可能是偶尔吸烟者能够在如此低的水平维持吸烟行为的原因。为了评估这一假设，我们研究了偶尔吸烟者和匹配的常规吸烟者体内尼古丁的消除动力学和药效学。在给受试者吸入统一剂量的烟草烟雾后，观察他们数小时内的血浆尼古丁水平和心血管反应。偶尔吸烟者确实表现出较低的慢性尼古丁耐受性，但仅在某些反应指标上如此。他们的尼古丁消除率与常规吸烟者相当。这一发现，再结合其他有关偶尔吸烟者吸烟模式和尼古丁吸收的数据，表明偶尔吸烟者在两支烟之间无法维持较高的血浆尼古丁水平，因此表明试图维持最低尼古丁低谷水平并非偶尔吸烟者吸烟的原因。
