Nicotine receptors as a possible marker for smoking-related sperm damage

Background: Several studies demonstrate that cigarette smoking has a negative effect on the reproductive health of both genders. The mechanisms by which it alters male gonadic function are not entirely clear. The combustion of cigarette produces a lot of chemical compounds that may be responsible for the negative impact of cigarette smoke on sperm parameters. In particular, the effects on semen of nicotine, a substance present in the tobacco plant and the main constituent of cigarette smoke, have been studied, showing that this alkaloid alters sperm parameters. Recently we investigated the mechanism by which nicotine damages sperm through the evaluation of the expression of nicotinic receptors subunits in human spermatozoa. Conclusion: 8 nAChR subunits found to date in mammals are expressed in human spermatozoa but, in non-smokers subjects, only α7 subunit is translated. Cigarette smoking may stimulate the expression of some subunits, not translated in non-smokers. Therefore, the presence in sperm of other nAChR subunits than α7 could represent a marker for smoking-related sperm damage.