Nicotine induced autophagy of Leydig cells rather than apoptosis is the major reason of the decrease of serum testosterone.

A new report has shown that nicotine exposure can decrease serum testosterone by apoptosis in Leydig cells; however, in our previous studies, we have almost never observed apoptosis there. The purpose of this study is to ensure whether apoptosis or autophagy in Leydig cells occurred. Our results confirmed again that the concentration of testosterone in the sera of nicotine-treated mice statistically decreased (P < 0.