Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
Department of MTC, Karolinska Institute, Solna, Sweden.
Nitric Oxide. 2020 Oct 1;103:1-3. doi: 10.1016/j.niox.2020.06.005. Epub 2020 Jun 23.
It has long been suggested that NO may inhibit an early stage in viral replication. Furthermore, in vitro tests have shown that NO inhibits the replication cycle of severe acute respiratory syndrome coronavirus. Despite smoking being listed as a risk factor to contract Covid-19, only a low proportion of the smokers suffered from SARS-corona infection in China 2003, and from Covid-19 in China, Europe and the US. We hypothesize, that the intermittent bursts of high NO concentration in cigarette smoke may be a mechanism in protecting against the virus. Mainstream smoke from cigarettes contains NO at peak concentrations of between about 250 ppm and 1350 ppm in each puff as compared to medicinal use of no more than 80 to a maximum of 160 ppm. The diffusion of NO through the cell wall to reach the virus should be significantly more effective at the very high NO concentration in the smoke, according to classic laws of physics. The only oxide of nitrogen in the mainstream smoke is NO, and the NO concentration that is inhaled is very low or undetectable, and methemoglobin levels are lower in smokers than non-smokers, reasonably explained by the breaths of air in between the puffs that wash out the NO. Specialized iNO machines can now be developed to provide the drug intermittently in short bursts at high concentration dose, which would then provide both a preventative drug for those at high risk, as well as an effective treatment, without the health hazards associated with smoking.
长期以来，人们一直认为 NO 可能抑制病毒复制的早期阶段。此外，体外试验表明，NO 抑制严重急性呼吸系统综合症冠状病毒的复制周期。尽管吸烟被列为感染新冠病毒的风险因素，但 2003 年中国只有少数吸烟者感染 SARS 冠状病毒，而在中国、欧洲和美国，也只有少数吸烟者感染新冠病毒。我们假设，香烟烟雾中间歇性爆发的高浓度 NO 可能是一种预防病毒的机制。与医学上使用的不超过 80 至最大 160ppm 的 NO 相比，香烟主流烟雾中的 NO 峰值浓度在每次吸烟时可达到 250ppm 至 1350ppm 之间。根据经典物理定律，NO 通过细胞壁扩散到病毒的速度应该在烟雾中非常高的 NO 浓度下显著提高。主流烟雾中的唯一氮氧化物是 NO，吸入的 NO 浓度非常低或无法检测到，并且吸烟者的高铁血红蛋白水平低于不吸烟者，这可以合理地解释为吸烟之间的空气呼吸可以将 NO 冲洗掉。现在可以开发专门的 iNO 机器，以高浓度剂量间歇性地提供这种药物，这将为高风险人群提供一种预防药物，同时也为他们提供一种有效的治疗方法，而不会带来与吸烟相关的健康危害。
